Order of the Head of the Novosibirsk State University on awarding a Diploma to A.P. Ershov on his 50th birthday. (With a hand-written Ershov's explanatory remark addressed to his mother.) Date: 21.04.1981 Original document language: Russian Authors: Anatoli Panteleyevich Derevianko Addressee: Andrei Petrovich Ershov
