!!!Zsigmond Ritoók

[Obituary|https://mta.hu/mta_hirei/elhunyt-ritook-zsigmond-az-mta-rendes-tagja-115217], Hungaria Academy of Sciences (in Hungarian)\\
[Obituary|https://www.elte.hu/elhunyt-ritook-zsigmond], Eötvös Loránd University (ELTE) (in Hungarian)\\