Congratulations in prose and verses from programmers of the Institute of Cybernetics of the Ukrainian Academy of Sciences and from E.Yushchenko personally. (With a hand-written Ershov's explanatory remark addressed to his mother.) Date: 18.04.1981 Original document language: russian Authors: Ekaterina Logvinovna Yuschenko Organizations: Inst. of Cybernetics of the Ukrainian Ac. Sci. Addressee: Andrei Petrovich Ershov
