!!Publications by Arto Salomaa after 1990 
(Books in italics)
\\ \\ 
*1990 
**''Introduction à l'Informatique Théorique, Calculabilité et Complexité''. Armand Colin, Paris, ix+372 pp. 
**''Public-Key Cryptography''. Springer-Verlag, Berlin, New York, London, Paris, Tokyo, x+245 pp. 
**Formal languages and power series. In Handbook of Theoretical Computer Science, Vol. II (J. van Leeuwen, ed.), Elsevier Science Publishers B.V., Vol. B, 103-132. 
**(ed.) Special issue of Theoretical Computer Science, Vol. 71, no. 1, 174 pp. 
**(with G. Rozenberg) L-systems. In Encyclopedia of Mathematics, Vol. 5, 325-327. Kluwer Academic Publishers. 
**Decidability in finite automata. EATCS Bulletin 41, 175-183. 
**Decision problems arising from knapsack transformations. Acta Cybernetica 9, 419-440. 
**Interaction. Japan Computer Science Association Reports 15, 4-8. 
**Formal power series: a powerful tool for theoretical informatics. Proceedings of the 300-Year Festival Congress of the Hamburg Mathematical Association, 1033-1048. 
**(with L. Santean) Secret selling of secrets with many buyers. EATCS Bulletin 42, 178-186. 
**(with G. Rozenberg) Mathematical theory of computation. Encyclopedia of Mathematics, Vol. 6, 146-148. 
**From number theory to cryptography: RSA. Arkhimedes 42, 526-535. 
**Mathematics and natural sciences. In: Finnish Council of University Rectors (ed.), University Research in Finland, 10-13. 
**(ed. with W. Brauer and G. Rozenberg) 4 volumes of EATCS Monographs on Theoretical Computer Science, Springer-Verlag. 

*1991 
**(with G. Rozenberg) Post correspondence problem. Encyclopedia of Mathematics, Vol. 7, 252-253. 
**(with H. Maurer and D. Wood) Bounded delay L codes. Theoretical Computer Science 84, 265-279. 
**A deterministic algorithm for modular knapsack problems. Theoretical Computer Science 88, 127-138. 
**(ed.) Special issue "Formal Language Theory" of Discrete Applied Mathematics, Vol. 32, no. 2, 142 pp. 
**(with H. Nurmi) A cryptographic approach to the secret ballot. Behavioral Science 36, 34-40. 
**Many aspects of formal languages. Information Sciences, Vol. 57-58 (Special issue "Information Sciences: Past, Present, Future"), 119-129. 
**(with H. Nurmi) Salaiset vaalit ja matemaattinen kryptografia. Politiikka 1, 11-18. 
**L codes and L systems with immigration. EATCS Bulletin 43, 124-130. 
**(with K. Salomaa and S. Yu) Primality types of instances of the Post correspondence problem. EATCS Bulletin 44, 226-241. 
**(with J. Honkala) L morphisms: bounded delay and regularity of ambiguity. Springer Lecture Notes in Computer Science 510, 566-574. 
**(with H. Nurmi and L. Santean) Secret ballot elections in computer networks. Computers and Security 10, 553-560. 
**Verifying and recasting secret ballots in computer networks. Springer Lecture Notes in Computer Science 555, 283-289. 
**(ed. with W. Brauer and G. Rozenberg) 3 volumes of EATCS Monographs on Theoretical Computer Science, Springer-Verlag. 

*1992 
**(with M. Andrasiu, A. Atanasiu and G. Paun) A new cryptosystem based on formal language theory. Bull. Math. Soc. Sci. Math. Roumaine 36 (84) 3-16. 
**(with G. Paun and S. Vicolov) On the generative capacity of parallel communicating grammar systems. **International Journal of Computer Mathematics 45, 45-59. 
**(with J. Honkala) Characterization results about L codes. RAIRO 26, 287-301. 
**(with L. Kari, S. Marcus and G. Paun) In the prehistory of formal language theory: Gauss languages. EATCS Bulletin 46, 124-139. 
**(with G. Paun) Decision problems concerning the thinness of DOL languages. EATCS Bulletin 46, 171-181. 
**(with L. Kari and G. Paun) Semi-commutativity sets for morphisms on free monoids. Bull. Math. Soc. Sci. Math. Roumaine 36 (84), 293-307. 
**(with H. Nurmi) Secret Ballot Elections and Public-Key Cryptosystems. European Journal of Political Economy 8, 295-303. 
**(with H. Nurmi) Tietokonevaalit ja Tengvallin credo. Politiikka XXXIV, 199-201. 
**(with G. Paun) Semi-commutativity sets - a cryptographically grounded topic. Bull. Math. Soc. Sci. Math. Roumaine 35, 255-270. 
**(ed. with G. Rozenberg) ''Lindenmayer Systems''. Springer-Verlag, 514 pp. 
**(ed. with W. Brauer and G. Rozenberg) 3 volumes of EATCS Monographs on Theoretical Computer Science, Springer-Verlag. 
**''Public-Key Cryptography''. Japanese translation published by Tokyo Denki Daigaku Shuppankyoku. 
**''Nhap Mon Tin Hoc Ly Thuyet. Tinh Toan Vacac Otomat''. Vietnamese translation of ''Computation and Automata'' published by Nha Xvat Ban Khoa Hoc Va Ky Thuat, Hanoi. 
**Recent trends in the theory of formal languages. Proceedings of the Conference "Salodays in Theoretical Computer Science", Bucharest, May 1992, 3 pp. 
**Different aspects of the Post correspondence problem. EATCS Bulletin 47, 154-165. 
**(with E. Neuhold, A. Björck, D. Parnas and D. Patterson) Informatikk: Research and Teaching in Norway. A critical evaluation. NAVF, Norway, 66 pp. 
**Nhung huong phat trien moi trong tin hoc ly thuyet. In the Vietnamese translation of ''Computation and Automata'', 394-404. 

*1993 
**Simple reductions between D0L language and sequence equivalence problems. Discrete Applied Mathematics 41, 271-274. 
**(with A. Mateescu) PCP-prime words and primality types. RAIRO 27, 57-70. 
**(with M. Andrasiu, J. Dassow and G. Paun) Language-theoretic problems arising from Richelieu cryptosystems. Theoretical Computer Science 116, 339-357. 
**(with G. Rozenberg) Undecidability. In Encyclopedia of Mathematics, Vol. 9, 310-311. Kluwer Academic Publishers. 
**''Criptografie Cu Chei Publice''. Romanian translation of ''Public-Key Cryptography'', published by Editura Militara, 253 pp. 
**(ed. with G. Rozenberg) ''Current Trends in Theoretical Computer Science''. World Scientific, Singapore, ix+628 pp. 
**(with L. Kari, S. Marcus and G. Paun) In the prehistory of formal language theory: Gauss languages. In: G. Rozenberg and A. Salomaa (eds.), Current Trends in Theoretical Computer Science, World Scientific, 551-562. 
**What Emil said about the Post Correspondence Problem. In: G. Rozenberg and A. Salomaa (eds.), Current Trends in Theoretical Computer Science, World Scientific, 563-571. 
**Decidability in finite automata. In: G. Rozenberg and A. Salomaa (eds.), Current Trends in Theoretical Computer Science, World Scientific, 572-578. 
**(with A. Mateescu) On simplest possible solutions for Post correspondence problems. Acta Informatica 30, 441-457. 
**(with J. Dassow and G. Paun) On thinness and slenderness of L Languages. EATCS Bulletin 49, 152-158. 
**(with J. Dassow and G. Paun) Grammars based on patterns. International Journal of Foundations of Computer Science 4, 1-14. 
**(with J. Dassow, A. Mateescu and G. Paun) Regularizing context-free languages by AFL operations: concatenation and Kleene closure. Acta Cybernetica 10, 243-253 
**(with L. Kari) 50 EATCS Bulletins. EATCS Bulletin 50, 5-12. 
**(with G. Paun) Remarks concerning self-reading sequences. EATCS Bulletin 50, 229-233. 
**(with G. Paun) Closure properties of slender languages. Theoretical Computer Science 120, 293-301. 
**(with H. Nurmi) Cryptographic protocols for Vickrey auctions. Ann. Univ. Turku, B 200, 9-22, and Group Decision and Negotiation 2, 263-273. 
**(with H. Nurmi) Cancellation and Reassignment of Votes in Secret Ballot Elections. European Journal of Political Economy 9, 427-435. 
**(with T. Jiang, K. Salomaa and S. Yu) Inclusion is undecidable for pattern languages. Springer Lecture Notes in Computer Science 700, 301-312. 
**Pattern languages: problems of decidability and generation. Springer Lecture Notes in Computer Science 710, 121-132. 
**(with A. Mateescu) Post correspondence problem: primitivity and interrelations with complexity classes. Springer Lecture Notes in Computer Science 711, 174-184. 
**(ed. with W. Brauer and G. Rozenberg) 3 volumes of EATCS Monographs on Theoretical Computer Science, Springer-Verlag. 
**(with J. Dassow and G. Paun) On the union of OL languages. Information Processing Letters 47, 59-63. 
**(with L. Kari, A. Mateescu and G. Paun) Deletion sets. Fundamenta Informaticae 19, 355-370. 
**(with L. Kari, A. Mateescu and G. Paun) Grammars with oracles. Annals of University of Iasi II, Informatica, 3-12. 

*1994 
**(with G. Rozenberg) ''Cornerstones of Undecidability''. Prentice Hall, New York, London, Toronto, Sydney, Tokyo, Singapore, xvi+197 pp. 
**(ed. with G. Rozenberg) ''Developments in Language Theory''. World Scientific, Singapore, New Jersey, London, Hong Kong, xii+492 pp. 
**(with C. Calude) Algorithmically coding the universe. In G. Rozenberg and A. Salomaa (ed.), ''Developments in Language Theory'', World Scientific, 472-492. 
**(with S. Marcus, A. Mateescu and G. Paun) On symmetry in strings, sequences and languages. International Journal of Computer Mathematics 54, 1-13. 
**(with A. Mateescu and V. Mitrana) Dynamical teams of cooperating grammar systems. Annals of University of Bucharest, Mathematica 43, 3-14. 
**(with A. Mateescu) Nondeterminism in patterns. Springer Lecture Notes in Computer Science 775, 661-668. 
**(with G. Paun and G. Rozenberg) Contextual grammars: erasing, determinism, one-side contexts. In G. Rozenberg and A. Salomaa (ed.), Developments in Language Theory, World Scientific, 370-389. 
**(with T. Jiang, E. Kinber, K. Salomaa and S. Yu) Pattern languages with and without erasing. International Journal of Computer Mathematics 50, 147-163. 
**(with C. Calude and H. Maurer) Journal of Universal Computer Science. Journal of Universal Computer Science, Vol. 0, No. 0, 109-117. 
**(with A. Mateescu) Finite degrees of ambiguity in pattern languages. RAIRO 28, 233-253. 
**(with H. Nurmi) Conducting secret ballot elections in computer networks: problems and solutions. Annals of Operations Research 5, 185-194. 
**(with H. Nurmi) The nearly perfect auctioner: cryptographic protocols for auctions and bidding. In: Sixto Rios (ed.) Decision Theory and Decision Analysis: Trends and Challenges, Kluwer, Dordrecht. 
**Patterns. EATCS Bulletin 54, 194-206. 
**Patterns and pattern languages. In C. Calude, M. Lennon and H. Maurer (eds.), ''Salodays in Auckland'', Proceedings, Auckland Univ., 8-12. 
**Machine-oriented Post Correspondence Problem. In C. Calude, M. Lennon and H. Maurer (eds.) ''Salodays in Auckland'', Proceedings, Auckland Univ., 13-14. 
**(ed. with W. Brauer and G. Rozenberg) 3 volumes of EATCS Monographs on Theoretical Computer Science. 

*1995 
**(with L. Kari, A. Mateescu and G. Paun) Teams in cooperating grammar systems. Journal of Experimental and Theoretical AI 7, 347-359. 
**(with L. Kari, A. Mateescu and G. Paun) Multi-pattern languages. Theoretical Computer Science 141, 253-268. 
**(with G. Paun and G. Rozenberg) Contextual grammars: modularity and leftmost derivation. In: G. Paun (ed.) Mathematical Aspects of Natural and Formal Languages. World Scientific, 375-392. 
**(with T. Jiang, K. Salomaa and S. Yu) Decision problems concerning patterns. Journal of Computer and System Sciences 50, 53-63. 
**(with L. Kari, A. Mateescu and G. Paun) On parallel deletions applied to a word. RAIRO 29, 129-144. 
**(with G. Paun and G. Rozenberg) Grammars based on the shuffle operation. Journal of Universal Computer Science, Vol. 1, No. 1, 67-82. 
**(with E. Csuhaj-Varju and G. Paun) Conditional tabled eco-grammar systems versus (E)TOL systems. Journal of Universal Computer Science, Vol. 1, No. 5, 252-268. 
**(with A. Mateescu, K. Salomaa and S. Yu) Lexical analysis with a simple finite-fuzzy-automaton model. Journal of Universal Computer Science, Vol. 1, No. 5, 292-311. 
**Developmental models for artificial life: basics of L systems. In: G. Paun (ed.) Artificial Life: Grammatical Models. Black Sea University Press, 22-32. 
**Stagnation and malignancy: growth patterns in artificial life. In: G. Paun (ed.) Artificial Life: Grammatical Models. Black Sea University Press, 104-115. 
**Kansainvälistyminen. In: M. Wiberg (ed.) Yliopisto uusiksi. Gaudeamus, 192-201. 
**Return to patterns. EATCS Bulletin 55, 144-157. 
**(ed. with W. Brauer and G. Rozenberg) 4 volumes of EATCS Monographs on Theoretical Computer Science. 
**(with L. Kari and G. Rozenberg) Generalized DOL trees. Acta Cybernetica 12, 1-10. 
**(with A. Mateescu, G. Paun and G. Rozenberg) Parikh Prime Words and GO-Like territories. Journal of Universal Computer Science, Vol. 1, No. 12, 790-810. 
**(with A. Mateescu, K. Salomaa and S. Yu) P, NP and Post Correspondence Problem. Information and Computation, Vol. 121, No. 2, 135-142. 
**(with G. Paun) Thin and slender languages. Discrete Appl. Math. 61, 257-270. 
**Julkiset salat - tietosuojauksen matematiikkaa. In: J. Rydman (ed.), Tutkimuksen etulinjassa, WSOY (1995), 301-315. 
**From Parikh vectors to GO territories. EATCS Bulletin 56, 89-95. 
**(with A. Ehrenfeucht, L. Ilie, G. Paun and G. Rozenberg) On the generative capacity of certain classes of contextual grammars. In G. Paun (ed.), Mathematical Linguistics and related topics. Ed. Academiei, Bucharest, 105-118. 

*1996 
**(with Cunsheng Ding and Dingyi Pei) ''Chinese Remainder Theorem. Applications in Computing, Coding, Cryptography''. World Scientific, Singapore, viii+213 pp. 
**''Kriptografia s otkrytym kljutsom''. (Russian translation of ''Public-Key Cryptography''.) Izdatelstvo "Mir", Moscow, 318 pp. 
**''Public-Key Cryptography'', ''Second, Enlarged Edition''. Springer-Verlag, Berlin, Heidelberg, New York, x+271 pp. 
**(ed. with J. Dassow and G. Rozenberg) ''Developments in Language Theory II. At the Crossroads of Mathematics, Computer Science and Biology''. World Scientific, Singapore, x+491 pp. 
**(with T. Nishida) On slender OL languages. Theoretical Computer Science 158, 161-176. 
**(with V. Mitrana, G. Paun and G. Rozenberg) Pattern systems. Theoretical Computer Science 154, 183--201. 
**(with A. Mateescu) Views on linguistics. EATCS Bulletin 58, 148-154. 
**(ed. with G. Rozenberg) Special issue: Formal Language Theory. Fundamenta Informaticae, Vol. 25, Numbers 3,4. 
**(with G. Paun) Self-reading sequences. Amer. Math. Monthly 103, 166-168. 
**(with C. Martin-Vide, J. Miquel-Verges and G. Paun) An attempt to define the ambiguity of internal contextual languages. II International Conference on Mathematical Linguistics (ICML), Tarragona. 
**Slenderness and immigration: new aspects of L systems. Publ. Math. Debrecen 48/3-4, 411-420. 
**(with G. Paun and G. Rozenberg) Contextual grammars: parallelism and blocking of derivation. Fundamenta Informaticae 25, 381-397. 
**(with C. Ding) Cooperatively distributed ciphering and hashing. TUCS Technical Report 13, Computers and Artificial Intelligence 15, 233-245. 
**(with S. Dumitrescu and G. Paun) Languages associated to finite and infinite sets of patterns. Rev. Roum. Math. Pures Appl. 41, 607-625. 
**(with L. Kari and G. Paun) The power of restricted splicing with rules from a regular language. J. Univ. Computer Sci., Vol. 2, No 4, 224-240. 
**(with G. Paun and G. Rozenberg) Contextual grammars: deterministic derivations and growth functions. Rev. Roum. Math. Pures Appl. 41, 83-108. 
**(with G. Paun and G. Rozenberg) Computing by splicing. Theoretical Computer Science 168, 321-336. 
**(with G. Paun and G. Rozenberg) Restricted use of the splicing operation. Intern. J. Computer Math. 60, 17-32. 
**(with G. Paun and G. Rozenberg) Pattern grammars. Automata, Languages, Combinatorics 1, 219-235. 
**Conjugate words, cuts of the deck and cryptographic protocols. EATCS Bulletin 59, 137-149. 
**(with G. Paun) DNA computing based on the splicing operation. Mathematica Japonica 43, 607-632. 
**(with C. Martin-Vide, A. Mateescu and J. Miquel-Verges) Quasi shuffle Marcus grammars. Actas del XII Congr. Lenguajes Naturales y Lenguajes Formales, Barcelona, 495-500. 
**(with M. Lipponen) Simple words in equality sets. TUCS Technical Report 39, EATCS Bulletin 60, 123-143. 
**(with G. Rozenberg) Watson-Crick complementarity, universal computations and genetic engineering. Leiden University, Department of Computer Science Technical Report 96-28. 
**(ed. with W. Brauer and G. Rozenberg) 3 volumes of EATCS Texts and Monographs in Theoretical Computer Science. 
**Norsunluutornista kauppamatkustajaksi. In P. Neittaanmäki (ed.), ''Muutos tieteen maailmassa: tutkimus, tiede ja yliopistot 2010'', Atena Kustannus, 180-189. 
**(with L. Ilie) On regular characterizations of languages using grammar systems. Acta Cybernetica 12, 411-425. 
**(with V. Mihalache) Growth Functions and Length Sets of Replicating Systems. Acta Cybernetica 12(3), 235-247. (Also published as TUCS Technical Report 23.) 
**(with A. Ehrenfeucht, A. Mateescu, G. Paun and G. Rozenberg) On representing RE languages by one-sided internal contextual languages. Acta Cybernetica 12, 217-233. 
**(with A. Mateescu) Parallel Composition of Words with Re-entrant Symbols. Annals of University of Bucharest 1, 71-80. 

*1997 
**(ed. with G. Rozenberg) Formal Languages, a special issue. Theoretical Computer Science 183, 1. 
**(with A. Mateescu and G. Rozenberg) Geometric Transformations on Language Families: The Power of Symmetry. International Journal of Foundations of Computer Science 8(1), 1-14. 
**(ed. with G. Rozenberg) ''Handbook of Formal Languages'', Vol. 1 - Word, Language, Grammar. Springer-Verlag, Berlin, Heidelberg, xxiv+873 pp. 
**(ed. with G. Rozenberg) ''Handbook of Formal Languages'', Vol. 2 - Linear Modeling: Background and Application. Springer-Verlag, Berlin, Heidelberg, xxii+528 pp. 
**(ed. with G. Rozenberg) ''Handbook of Formal Languages'', Vol. 3 - Beyond Words. Springer-Verlag, Berlin, Heidelberg, xx+625 pp. 
**(with J. Dassow and G. Paun) Grammars with controlled derivations. In G. Rozenberg, A. Salomaa (eds.), ''Handbook of Formal Languages'', Vol. 2, Springer-Verlag, Berlin, Heidelberg, 101-154. 
**(with L. Kari and G. Rozenberg) L Systems. In G. Rozenberg, A. Salomaa (eds.), ''Handbook of Formal Languages'', Vol. 1, Springer-Verlag, Berlin, Heidelberg, 253-328. 
**(with A. Mateescu) Formal Languages: an Introduction and a Synopsis. In G. Rozenberg, A. Salomaa (eds.), ''Handbook of Formal Languages'', Vol. 1, Springer-Verlag, Berlin, Heidelberg, 1-39. 
**(with A. Mateescu) Aspects of Classical Language Theory. In G. Rozenberg, A. Salomaa (eds.), ''Handbook of Formal Languages'', Vol. 1, Springer-Verlag, Berlin, Heidelberg, 175-251. 
**(with G. Paun) Families Generated by Grammars and L Systems. In G. Rozenberg, A. Salomaa (eds.), ''Handbook of Formal Languages'', Vol. 1, Springer-Verlag, Berlin, Heidelberg, 811-861. 
**(ed. with G. Paun) ''New Trends in Formal Languages''. Lecture Notes in Computer Science, Vol. 1218, Springer-Verlag, Berlin, Heidelberg, ix+465 pp. 
**(with E. Csuhaj-Varju) Networks of Parallel Language Processors. In G. Paun, A. Salomaa (eds.), ''New Trends in Formal Languages'', Lecture Notes in Computer Science, Vol. 1218, Springer-Verlag, Berlin, Heidelberg, 299-318. 
**(with A. Mateescu, G.D. Mateescu and G. Rozenberg) Shuffle-Like Operations on omega-words. In G. Paun, A. Salomaa (eds.), ''New Trends in Formal Languages'', Lecture Notes in Computer Science, Vol. 1218, Springer-Verlag, Berlin, Heidelberg, 395-411. 
**Computability paradigms based on DNA complementarity. In V. Keränen (ed.), Innovation in Mathematics, Proc. 2nd Intern. Mathematica Symposium, Computational Mechanics Publications, Southhampton and Boston, 15-28. 
**(with C. Ding, V. Niemi and A. Renvall) Twoprime: A Fast Stream Ciphering Algorithm. In E. Biham (ed.), ''Fast Software Encryption'', Lecture Notes in Computer Science, Vol. 1267, Springer-Verlag, 88-102. 
**(with S. Dumitrescu and G. Paun) Pattern languages versus parallel communicating grammar systems. Intern. J. Found. Comp. Sci. 8,67-80. 
**(ed. with W. Brauer and G. Rozenberg) 2 volumes of EATCS Texts and Monographs in Theoretical Computer Science. 
**(ed. with J. Mycielski and G. Rozenberg) ''Structures in Logic and Computer Science''. Lecture Notes in Computer Science, Vol. 1261, Springer-Verlag, Berlin, Heidelberg, x+370 pp. 
**(with V. Mihalache) Lindenmayer and DNA: Watson-Crick DOL Systems. EATCS Bulletin 62, 160-175. (Also published as TUCS Technical Report 108.) 
**(with J. Dassow and V. Mitrana) Context-Free Evolutionary Grammars and Structural Language of Nucleic Acids. BioSystems 43, 169-177. (Also published as TUCS Technical Report 68.) 
**(with C. Martin-Vide, J. Miquel-Verges and G. Paun) Attempting to define the ambiguity of internal contextual languages. In C. Martin-Vide (ed.), Second Intern. Conf. on Mathematical Linguistics, John Benjamin, Tarragona, 47-69. 
**(with G. Paun and G. Rozenberg) Computing by splicing. Programmed and evolving splicing rules. In Proceedings of IEEE Intern. Conf. on Evolutionary Computing, Indianapolis, 273-277. 
**(with G. Paun) From DNA recombination to DNA computing via formal languages. In R. Hofestadt and T. Lengauer and M. Loffler and D. Schomburn (eds), ''Bioinformatics'', Lecture Notes in Computer Science, Vol. 1278, Springer-Verlag, Leipzig, 210-220. 
**(with A. Mateescu and G. Rozenberg) Syntactic and semantic aspects of parallelism. In C. Freksa and M. Jantzen (eds), ''Foundations of Computer Science; Potential-Theory-Cognition'', Lecture Notes in Computer Science, Vol. 1337, 79-105. 

*1998 
**''Public-Key Cryptography ''(Chinese translation). The National Defense Industry Press, Beijing. 
**(with A. Mateescu) Abstract Family of Languages. In M. Hazinwinkel (ed.), ''Encyclopedia of Mathematics'', Vol. 1, Kluwer Academic Publishers, 12-13. 
**(with A. Mateescu) Grammar Forms. In M. Hazinwinkel (ed.), ''Encyclopedia of Mathematics'', Vol. 1, Kluwer Academic Publishers, 272-273. 
**(with A. Mateescu, G. Paun and G. Rozenberg) Characterizations of recursively enumerable languages starting from internal contextual languages. Intern. J. Comp. Math. 66, 179-197. 
**(with A. Mateescu and G. Rozenberg) Shuffle on trajectories: Syntactic constraints. Theoretical Computer Science 197, 1-56. (Fundamental Study) 
**(with A. Mateescu, G. Paun and G. Rozenberg) Simple sticker systems. Discrete Applied Mathematics 84, 145-163. 
**(with V. Mihalache) Language-Theoretic Aspects of String Replication. International Journal for Computer Mathematics 66, 163-177. (Also published as TUCS Technical Report 51.) 
**(with L. Ilie) On well quasi orders of free monoids. Theoretical Computer Science 204, 131-152. 
**(with L. Ilie) 2-Testability and relabelings produce everything. Journal of Computer and System Sciences 56, 253-262. 
**(with L. Kari, G. Paun, G. Rozenberg and S. Yu) DNA computing, sticker systems, and universality. Acta Informatica 35, 401-420. 
**(with E. Csuhaj-Varju) Networks of language processors: parallel communicating systems. EATCS Bulletin, 66, 122-138. 
**Turing, Watson-Crick and Lindenmayer. Aspects of DNA complementarity. In C.S. Calude, J. Casti, M.J. Dinneen (eds), Unconventional Models of Computation, Springer-Verlag, 94-107. 
**(with T. Harju and A. Mateescu) Shuffle on Trajectories: The Schutzenberger Product and Related Operations. In L. Brim, J. Gruska and J. Zlatuska (eds), MFCS'98, Lecture Notes in Computer Science, Vol. 1450, Springer-Verlag, 503-511. 
**(with G. Paun and G. Rozenberg) ''DNA Computing. New Computing Paradigms''. Springer-Verlag. 
**(with C. Martin-Vide, G. Paun and G. Rozenberg) Universality results for finite H system and Watson-Crick finite automata. In G. Paun (ed.), Computing with Biomolecules. Theory and Experiments. Springer-Verlag, Singapore, 200-220. 
**(with C. Martin-Vide and G. Paun) Characterizations of RE languages by means of insertion grammars. Theoretical Computer Science 205, 195-205. 
**(with G. Paun and G. Rozenberg) Complementarity versus universality: keynotes of DNA computing. Complexity 4(1), 14-19. 
**(with H. Nurmi) A comparative overview of cryptographic voting protocols. Annals of Operations Research 84, 29-43. 
**(with R. Freund, G. Paun and G. Rozenberg) Bidirectional sticker systems. In R. B. Altman, A. K. Dunker, L. Hunter, T. E. Klein (eds), Pacific Symposium on Biocomputing, World Scientific, Singapore, 535-546. 

*1999 
**(ed. with G. Paun) ''Grammatical Models of Multi-Agent Systems''. Number 8 in Topics in Computer Mathematics, Gordon and Breach, London, viii+355 pp. 
**Events and languages. In C. S. Calude (ed.), People & Ideas in Theoretical Computer Science, Springer series in discrete mathematics and theoretical computer science, Springer-Verlag, 253-273. 
**(with C.Martin-Vide, G. Paun and G. Rozenberg) X-families: An approach to the study of families of syntactically similar languages. In C. Martin-Vide (ed.) Issues in Mathematical Linguistics, John Benjamins Publ.Co, Amsterdam, Philadelphia, 145-163. 
**(with R. Freund, G. Paun and G. Rozenberg) Watson-Crick finite automata. In Harvey Rubin, David Harlan Wood (ed.), DNA Based Computers III, Discrete Mathematics and Theoretical Computer Science, Vol. 48, 297-327, American Mathematical Society. 
**Watson-Crick walks and roads in D0L graphs. Acta Cybernetica 14, 179-192. 
**(with A. Mateescu) Many-valued truth functions, Cerny's conjecture and road coloring. EATCS Bulletin 68, 134-150. 
**(with V. Mihalache) Mathematical properties of a particular type of DNA recombination. Publicationes Mathematicae 54, Debrecen, 949-960. 
**Caesar and DNA. Views on cryptology. In G. Ciobanu, G. Paun (eds), Fundamentals of Computation Theory, FCT'99, Springer Lecture Notes in Computer Science, Vol. 1684, 39-53, Springer-Verlag. 
**(with G. Rozenberg) DNA computing: new ideas and paradigms. In J. Wiedermann, P. van Emde Boas, M. **Nielsen (eds), Automata, Languages and Programming, ICALP'99 Proceedings, Springer Lecture Notes in Computer Science, Vol. 1644, 106-118. 
**(with C. Martin-Vide, A. Mateescu and G. Rozenberg) Contexts on Trajectories. International Journal of Computer Mathematics 73, 15-36. (Also TUCS Technical Report 214.) 
**(with G. Paun) Characterizations of Recursively Enumerable Languages by Using Copy Languages. Revue Roumaine de Math. Pures et Appl. 44, 447-454. (Also TUCS Technical Report 130.) 
**(with G. Paun and G. Rozenberg) ''DNA Computing. New Computing Paradigms''. (Japanese translation). Springer-Verlag, Tokyo, x+444 pp. 

*2000 
**(with L. Ilie and G. Rozenberg) A characterization of poly-slender context-free languages. Theoretical Informatics and Applications 34, 77-86. (Also TUCS Technical Report 242.) 
**(with R. Freund and A. Mateescu) Algebraic representations for regular array languages. In C. Calude and G. Paun (eds.) Finite versus Infinite: Contributions to an Eternal Dilemma. Springer-Verlag, 127-148. 
**(with T. Nishida) A note on slender 0L languages. Theoretical Computer Science, 233, 279-286. Also TUCS Technical Report 123. 
**(with L. Ilie) On the expressiveness of subset-sum representations. Acta Informatica 36, 665-672. Also TUCS Technical Report 94. 
**(with L. Ilie, G. Paun and G. Rozenberg) On Strongly Context-Free Languages. Discrete Applied Mathematics 103, 153-165. Also TUCS Technical Reports 205 and 248. 
**(with G. Paun and G. Rozenberg) Membrane Computing with External Output. Fundamenta Informaticae 41, 313-340. Also TUCS Technical Report 218. 
**(with S. Yu) On the decomposition of finite languages. In G. Rozenberg and W. Thomas (eds.) Developments in Language Theory. World Scientific, 22-31. 
**Automata: glimpses from past and present. Bulletin of the European Association for Theoretical Computer Science 70, 148-155. 
**Depth of functional compositions. Bulletin of the European Association for Theoretical Computer Science 71, 143-150. 
**(with G. Paun) Languages and grammars. In K.H. Rosen (ed.) Handbook of Discrete and Combinatorial Mathematics. CRC Press, 1066-1077. 

*2001 
**(with V. Mihalache) Language-theoretic aspects of DNA complementarity. Theoretical Computer Science 250, 163-178. 
**(with C. Martin-Vide and A. Mateescu) Sewing contexts and mildly context-sensitive languages. In C. Martin-Vide and V. Mitrana (eds.) Where Mathematics, Computer Science, Linguistics and Biology Meet. Kluwer Academic Publishers, 75-84. 
**Iterated morphisms with complementarity on the DNA alphabet. In M. Ito, G. Paun and S. Yu (eds.) Words, Semigroups, Transductions. World Scientific Publ. Co., 405-420. Also TUCS Technical Report 390. 
**(ed. with G. Paun and G. Rozenberg) ''Current Trends in Theoretical Computer Science. Entering the 21st Century''. World Scientific Publ. Co., x+869 pp. 
**(with A. Mateescu) Many-valued truth functions, Cerny's conjecture and road coloring. In G.Paun, G.Rozenberg and A.Salomaa (eds.) Current Trends in Theoretical Computer Science. World Scientific Publ. Co., 693-707. 
**(with M. Lipponen) Simple words in equality sets. In G.Paun, G.Rozenberg and A.Salomaa (eds.) Current Trends in Theoretical Computer Science. World Scientific Publ. Co., 717-733. 
**(with. V. Mihalache) Lindenmayer and DNA: Watson-Crick D0L systems. In G.Paun, G.Rozenberg and A.Salomaa **(eds.) Current Trends in Theoretical Computer Science. World Scientific Publ. Co., 740-751. 
**(with. E Csuhaj-Varju) Networks of language processors: parallel communicating systems. In G.Paun, G.Rozenberg and A.Salomaa (eds.) Current Trends in Theoretical Computer Science. World Scientific Publ. Co., 791-810. 
**(ed. with D. Wood and S. Yu) ''A Half-Century of Automata Theory. Celebration and Inspiration''. World Scientific Publ. Co., vii+155 pp. 
**(with J. Honkala) Watson-Crick D0L systems with regular triggers. Theoretical Computer Science 259, 689-698. Also TUCS Technical Report 360. 
**Compositions over a finite domain: from completeness to synchronizable automata. In A. Salomaa, D. Wood, S. Yu (eds.) A Half-Century of Automata Theory. Celebration and Inspiration. World Scientific Publ. Co., 131-143. Also TUCS Technical Report 350. 
**(with T. Harju, O. Ibarra and J. Karhumäki) Decision questions concerning semilinearity, morphisms and commutation of languages. Springer Lecture Notes in Computer Science 2076, 579-590. Also TUCS Technical Report 376. 
**(ed. with C. Calude, G. Paun and G. Rozenberg) ''Multiset Processing. Mathematical, Computer Science, and Molecular Computing Points if View''. Lecture Notes in Computer Science, Vol. 2235, Springer-Verlag, Berlin, Heidelberg, viii+359 pp. 
**(with A. Mateescu, K. Salomaa and Sheng Yu) A sharpening of the Parikh mapping. Theoretical Informatics and Applications 35, 551-564. Also TUCS Technical Report 364. 

*2002 
**(with J. Dassow and V. Mitrana) Operations and language generating devices suggested by the genome evolution. Theoretical Computer Science 270, 701-738. 
**(ed. with W. Brauer, H. Ehrig and J. Karhumäki) ''Formal and Natural Computing. Essays Dedicated to Grzegorz Rozenberg''. Lecture Notes in Computer Science, Vol. 2300, Springer-Verlag, Berlin, Heidelberg, xxxvi+431 pp. 
**(with A. Mateescu) Nondeterministic trajectories. Springer Lecture Notes in Computer Science 2300, 96-106. 
**Generation of constants and synchronization of finite automata. Journal of Universal Computer Science 8, 332-347. 
**(ed. with W. Kuich and G. Rozenberg) ''Developments in Language Theory. Revised papers of DLT 2001, Wien''. Lecture Notes in Computer Science, Vol. 2995, Springer-Verlag, Berlin, Heidelberg, ix+399 pp. 
**(with G. Rozenberg) ICALP, EATCS and Maurice Nivat. Theoretical Computer Science 281, 25-30. 
**Uni-transitional Watson-Crick D0L systems. Theoretical Computer Science 281, 537-553. Also TUCS Technical Report 389. 
**(with M. Amos, G. Paun and G. Rozenberg) Topics in the theory of DNA computing. Theoretical computer Science 287, 3-38. 
**(with T. Harju, O. Ibarra and J. Karhumäki) Some decision problems concerning semilinearity and commutation. Journal of Computer and System Sciences 65, 278-294. 
**Synchronization of finite automata. Contributions to an old problem. Springer Lecture Notes in Computer Science 2566, 37-59. Also TUCS Technical Report 365. 
**(with A. Mateescu and Sheng Yu) Factorizations of languages and commutativity conditions. Acta Cybernetica, 15, 339-351. Also TUCS Technical Report 222. 

*2003 
**(with J. Csima and E. Csuhaj-Varju) Power and size of extended Watson-Crick L systems. Theoretical Computer Science 290, 1665-1678. Also TUCS Technical Report 424. 
**(with S. Chanson and C. Ding) Cartesian authentication codes from functions with optimal nonlinearity. Theoretical Computer Science 290, 1737-1752. 
**Composition sequences for functions over a finite domain. Theoretical Computer Science 292, 263-281. 
**(ed. with G. Paun, G. Rozenberg and C. Zandron) ''Membrane Computing''. Lecture Notes in Computer Science 2597, Springer-Verlag, Berlin, Heidelberg, New York, viii+421 pp. 
**(with P. Sosik) Watson-Crick D0L systems: the power of one transition. Theoretical Computer Science 301, 187-200. Also TUCS Technical Report 439. 
**(with E. Csuhaj-Varju, C. Martin-Vide and G. Paun) From Watson-Crick L systems to Darwinian P systems. Natural Computing 2, 299-318. 
**(with E. Csuhaj-Varju) Networks of Watson-Crick D0L systems. In M. Ito and T. Imaoka (eds.) Words, Languages and Combinatorics III, World Scientific Publ. Co., Singapore, 134-150. Also TUCS Technical Report 419. 
**Counting (scattered) subwords. EATCS Bulletin 81, 165-179. Also TUCS Technical Report 570. 

*2004 
**(with A. Mateescu and Sheng Yu) Subword histories and Parikh matrices. Journal of Computer and System Sciences 68, 1-21. Also TUCS Technical Report 481. 
**(ed. with C. Martin-Vide, G. Mauri, G. Paun and G. Rozenberg) ''Membrane Computing'', WMC 2003. Lecture Notes in Computer Science 2933, Springer-Verlag, Berlin, Heidelberg, New York, viii+383 pp. 
**Developmental languages versus DNA computing. In C. Martin-Vide, V. Mitrana and G. Paun (eds.) Formal Languages and Applications. Springer Studies in Fuzziness and Soft Computing 148, 457-469. Also TUCS Technical Report 482. 
**(with A. Mateescu) Matrix indicators for subword occurrences and ambiguity. International Journal of Foundations of Computer Science 15, 277-292. Also TUCS Technical Report 536. 
**(with D. Wood and S. Yu) On the state complexity of reversals of regular languages. Theoretical Computer Science 320, 315-329. Also TUCS Technical Report 571. 
**(ed. with G. Paun and G. Rozenberg) ''Current Trends in Theoretical Computer Science, The Challenge of the New Century. Vol. 1: Algorithms and Complexity''. World Scientific Publishing Company, xii+663 pp. 
**(ed. with G. Paun and G. Rozenberg) ''Current Trends in Theoretical Computer Science, The Challenge of the New Century. Vol. 2: Formal Models and Semantics''. World Scientific Publishing Company, xiii+627 pp. 
**Counting (scattered) subwords. In G. Paun, G. Rozenberg and A. Salomaa (eds.) Current Trends in Theoretical Computer Science, The Challenge of the New Century, Vol. 2, 495-510. World Scientific Publishing Company. 
**The Depth of Functional Compositions. In G. Paun, G. Rozenberg and A. Salomaa (eds.) Current Trends in Theoretical Computer Science, The Challenge of the New Century, Vol. 2, 589-598. World Scientific Publishing Company. 
**(with G. Paun and G. Rozenberg) ''DNA Computing. New Computing Paradigms'' (Chinese translation). Tsinghua University Press, xv+344 pp. 
**(with G. Paun and G. Rozenberg) ''DNK-Compjuter. Novaja paradigma vytsislenii''. (Russian translation). Izdatelstvo "Mir", 527 pp. 

*2005 
**(with C. Ding, P. Sole and X. Tian) Three constructions of authentication/secrecy codes. Journal of Pure and Applied Algebra 196, 149-168. 
**On the injectivity of Parikh matrix mappings. Fundamenta Informaticae 64, 391-404. Also TUCS Technical Report 601. 
**(ed. with G. Mauri, G. Paun, M.J. Perez-Jimenez and G. Rozenberg) ''Membrane Computing, 5th International Workshop''. Springer-Verlag, Berlin, Heidelberg, New York, ix+415 pp. 
**Connections between subwords and certain matrix mappings. Theoretical Computer Science 340, 188-203. 

*2006 
**(ed. with R. Freund, G. Paun and G. Rozenberg) ''Membrane Computing, 6th International Workshop''. Springer-Verlag, Berlin, Heidelberg, New York, ix+371 pp. 
**(with C. Ding) Secret sharing schemes with nice access structures. Fundamenta Informaticae 73, 51-63. 
**(with C. Ding) On some problems of Mateescu concerning subword occurrences. Fundamenta Informaticae 73, 65-79. 
**On languages defined by numerical parameters. In K.G. Subramanian, K. Rangarajan, M. Mukund (eds.): ''Formal Models, Languages and Applications''. World Scientific Publishing Company, Singapore and New York, 320-336 (Chapter 22). 
**Independence of certain quantities indicating subword occurrences. Theoretical Computer Science 362, 222-231. Also TUCS Technical Report 748. 
**(with S. Yu) Subword conditions and subword histories. Information and Computation 204, 174-1755. Also TUCS Technical Report 633. 
**(ed. with H.J. Hoogeboom, G. Paun, and G. Rozenberg) ''Membrane Computing, 7th International Workshop''. Springer-Verlag, Berlin, Heidelberg, New York, ix+555 pp. 

*2007 
**Subword balance in binary words, languages and sequences. Fundamenta Informaticae 75, 469-482. Also TUCS technical Report 774. 
**(with Y.-S. Han, K. Salomaa, D. Wood and S. Yu) On the existence of prime decompositions. Theoretical Computer Science 376, 60-69. 
**(with G. Paun and M.J. Perez-Jimenez) Spiking neural P systems: an early survey. International Journal of Foundations of Computer Science 18, 435-455. 
**(with K. Salomaa and S. Yu) State complexity of combined operations. Theoretical Computer Science 383, 140-152. 
**(ed. with G. Eleftherakis, P. Kefalas, G. Paun and G. Rozenberg) ''Membrane Computing, 8th International Workshop''. Springer-Verlag, Berlin, Heidelberg, New York, xi+453 pp. 
**(with G. Rozenberg) The Secret Number. An Exposition of Chaitin?s Theory. In Calude, S. (ed.) ''Randomness and Complexity, from Leibniz to Chaitin''. World Scientific Publ. Co., Singapore, 175-215. 
**Moisil and many-valued logic. In Iorgulescu, A, Marcus, S., Rudeanu, S. and Vaida, D. (eds.) ''Gr. C. Moisil and His Followers in the Field of Theoretical Computer Science''. Editura Academiei Romane, Bucharest, 29-39. 
**Alexandru Mateescu (1952-2005). An exceptional algebraic talent. In Iorgulescu, A, Marcus, S., Rudeanu, S. and Vaida, D. (eds.) ''Gr. C. Moisil and His Followers in the Field of Theoretical Computer Science''. Editura Academiei Romane, Bucharest, 481-483. 

*2008 
**(with K. Salomaa and S. Yu) Length codes, products of languages and primality. Springer Lecture Notes in Computer Science 5196, ''Language and Automata Theory and Applications'', 476-486. Also TUCS Technical Report 868. 
**(with Guangwu Liu, Carlos Martin-Vide and Sheng Yu) State complexity of basic language operations combined with reversal. Information and Computation 206, 1178-1186. 
**Subword histories and associated matrices. Theoretical Computer Sceince 407, 250-257. Also TUCS Technical Report 869. 

*2009
**(ed. with D. Corne, P. Frisco, G. Paun and G. Rozenberg) ''Membrane Computing, WMC 2008.'' Springer Lecture Notes in Computer Science 5391, Berlin, Heidelberg, New York, ix+403 pp.
**Characteristic words for Parikh matrices. In Esik, Z. and Fulop, Z. (eds.) ''Automata, Formal Languages and Related Topics. Dedicated to Ference Gecseg on the occasion of his 70th birthday''. Institute of Informatics, University of Szeged, 117-127.
**(ed. with A. Condon, D. Harel, J. Kok and E. Winfree) ''Algorithmic Bioprocesses.'' Natural Computing Series, Springer-Verlag, Berlin, Heidelberg, x+742 pp.
**Grzegorz Rozenberg: a magical scientist and brother. In A.Condon, D. Harel, J. Kok, A. Salomaa and E. Winfree (eds.) ''Algorithmic Bioprocesses,'' Springer-Verlag, 3--11.
**Upper triangular matrices and subword occurrences. Scientiae Mathematicae Japonicae 70, 293--300.
**(with K.  Salomaa and S.  Yu) Variants of codes and indecomposable languages. Information and Computation 207, 1340--1349.

*2010
**(ed. with G. Paun and G. Rozenberg) ''The Oxford Handbook of Membrane Computing.'' Oxford University Press, Oxford, New York, xviii+672 pp.
**(ed. with  G. Paun, M. Perez-Jimenez, A. Riscos-Nunez and G. Rozenberg)''Membrane Computing, WMC 2009.''  Springer Lecture Notes in Computer Science 5957, Berlin, Heidelberg, New York, ix+487 pp.
**(with G. Paun and G. Rozenberg) Computability elements for membrane computing. In G. Paun, G. Rozenberg  and A.Salomaa (eds.) ''The Oxford Handbook of Membrane Computing.'' Oxford University Press, Oxford, New York, 58-82.
**(with S. Yu) Subword occurrences, Parikh matrices and Lyndon images. International Journal of Foundations of Computer Science Vol. 21, 91-111.
**Criteria for the matrix equivalence of words. Theoretical Computer Science 411,1818--1827.
** Subword balance, position indices and power sums. Journal of Computer and System Sciences, 76, 861-871.
** Ordered catenation closures and decompositions of languages related to a language of Derick Wood. Journal of Universal Computer Science 16,  821-832.

*2011
**Power sums associated with certain recursive procedures on words. International Journal of Foundations of Computer Science 22, 261-272.
**(ed. with M. Gheorhe, T. Hinze, G. Paun, and G. Rozenberg)''Membrane Computing, CMC 2010.'' Springer Lecture Notes in Computer Sceince 6051, ix+393 pp.
** (ed. with C. Calude and G. Rozenberg) ''Rainbow of Computer Science. Festschrift dedicated to Hermann Maurer.'' Springer Lecture Notes in Computer Science 6570, xii+285 pp.
** On some biologically motivated control devices for parallel rewriting. Springer Lecture Notes in Computer Sceince 6610,181-190.
** (with K. Salomaa and S. Yu) Undecidability of the state complexity of composed regular operations. Springer Lecture Notes in Computer Science 6638, 489-498.

*2012
**(ed. with G. Paun, G. Rozenberg and S. Verlan) ''Membrane Computing, CMC 2011.'' Springer Lecture Notes in Computer Science 7184, ix+477 pp.
** On state sequences defined by reaction systems. Springer Lecture Notes in Computer Science 7230, 271-282.
** Composition sequences and synchronizing automata. ''Computation, Physics and Beyond.'' Springer Lecture Notes in Computer Science 7160, 403-416.
** Subword occurrences, weighted automata and iterated morphisms, especially the Fibonacci morphism. Theoretical Computer Science 432, 85-93.
** Mirror images and schemes for the maximal complexity of non-determinism. Fundamenta Informaticae 116, 237-249.
** Undecidability of state complexities using mirror images. ''Languages Alive.'' Springer Lecture Notes in Computer Science 7300, 221-235.
** Functions and sequences generated by reaction systems. Theoretical Computer Science 466, 87-96.
** (with C.S. Calude and F.W. Meyerstein) The universe is lawless or ''Panton chrematon metron anthropon einai''. In H. Zenil (ed.) ''A Computable Universe.'' World Scientific Publishing Company, Singapore and New York, 527-540.
*2013
** (ed. with E. Csuhaj-Varju, M. Gheorghe, G. Rozenberg and G. Vaszil) ''Membrane Computing, CMC 2012.'' Springer Lecture Notes in Computer Scince 7762, xii+425 pp.
** Functional constructions between reaction systems and propositional logic. International Journal of Foundations of Computer Science 24, 147-159.
** (with K. Salomaa and S. Yu) Undecidability of state complexity. International Journal of Computer Mathematics 90, 1310-1320.
** Minimal and almost minimal reaction systems. Natural Computing 12, 369-376.
*2014
** (ed. with A. Alhasov, S. Cojokaru, M. Gheorghe, Y. Rogozhin and G. Rozenberg) ''Membrane Computing, CMC 2013.'' Springer Lecture Notes in Computer Science 8340, x+321 pp. 
** Compositions of  reaction  systems. Journal  of  Automata, Languages  and Combinatorics  19,  279--290.
** Minimal reaction systems defining subset  functions. In C. Calude, R. Freivalds, K. Iwama (eds.) ''Computing with New Resources''. Springer LNCS 8808, 436-446.
** (ed. with G. Paun and G. Rozenberg)  ''Discrete Mathematics and Computer Science''. Editura Academiei Romane, vii+308 pp.
** On axiomatizations of general many-valued propositional calculi. In G. Paun, G. Rozenberg and A. Salomaa (eds.) ''Discrete Mathematics and Computer Science'', Editura Academiei Romane, Bucuresti, 259-270. --
*2015 
** (ed. with M. Gheorghe, G. Rozenberg, P. Sosik and C. Zandron) ''Membrane Computing, CMC 2014.'' Springer Lecture Notes in Computer Science 8961, 305+xix pp.
** Applications of  the  Chinese remainder  theorem to  reaction  systems  with  duration. Theoretical  Computer  Science 598,  15-22.
** On  a  Cauchy-type  inequality  for subword  occurrences. Analele Universitate Bucuresti 62, Nr. 2, 101-112.
** Two-step  simulations of reaction  systems  by minimal ones. Acta Cybernetica  22, 293-311.
** (ed. with M. Gheorghe, I.Petre, M.J. Pérez-Jiménez and  G.Rozenberg) ''Multidisciplinary Creativity. Homage  to Gheorghe Paun  on His  65th Birthday.'' Editura Spandugino, Bucharest, 334+x pp.
*2017
** (With Yo-Sub Han and  Kai  Salomaa) Ambiguity, non-determinism and state complexity of  finite automata. Acta Cybernetica 23, 141-157.
** Minimal reaction  systems: duration  and  blips. Theoretical Computer Science 682, 208-216.
** The depth  of  closed  classes of truth function  in many-valued logic. In:  S. Konstantinidis, N. Moreira, R.Reis and J. Shallit (eds.) ''The Role of Theory in Computer Science'', World Scientific,  203-216.
*2018 
** From  infinite  to finite by identifying variables in many-valued logic. Journal on Automata, Languages and Combinatorics  23,  293-301.
** On  bases  of  many-valued truth  functions. In: A. Bellow,  C. Calude and T. Zamfirescu (eds.) ''Mathematics Almost Everywhere'', World  Scientific, 3-16.
** Parikh  matrices: subword  indicators and  degrees  of  ambiguity. In:  H.J. Böckenhauer, D. Komm and W. Unger (eds.) ''Adventures between Lower Bounds and Higher  Altitudes'', Springer  Lecture  Notes  in  Computer  Science Vol. 11011, 100-112.
**  (with G. Paun, I. Petre and G.Rozenberg) From finite state grammars to natural computing. In memory of  Solomon Marcus. Theoretical Computer Science 701, 2-7.
**  (with G. Paun  and  G. Rozenberg) Preface. Fundamenta Informaticae    154(1-4), vii.
*2019
**  (ed. with M. Gheorghe, G.Roznberg and C. Zandron) Membrane Computing, CMC2017. Springer  Lecture  notes  in  Computer Science 10725.
** (with C.Diaz, A. Riscos-Nuaez, G. Paun  and G.  Rozenberg)  Enjoying natural computing.   Esays dedicated to Mario de Jesus Perez-Jimenez. Springer Lectere Notes  in  Computer  Science 11270.
** (ed. with T.Hinze, G. Rozenberg and C. Zandron) Membrane Computing CMC 2018. Springer Lecture  Notes in Computer Science 11399.
*2020
** (with M.  Gheorghe, M. Perez-Jimenez and G.Rozenberg) Preface  of  the  special   issue for G. Paun's 70th Anniversary. Journal  of  Membrane  Computing 2(4) 227-229.
*2021
** (with L. Kari, I. Petre and G.Rozenberg) A fascinating rainbow  of  computation. Theoretical Computer  Science 862, 1-2
** (ed.  with R. Freund, T-O Ishdori, G. Rozenberg and C. Zandron) Membrane Computing CMC 2020. Springer Lecture Notes in Computer Science 12687,
*2023
** (with K. Salomaa and T.J. Smith) Descriptional complexity of  finite  automata -selected highlights. CoRRabs/2301.03708(2023)