Proof of the article "40 years later, 30 years later, 20 years later...TODAY!" in memory of an outstanding engineer and great patriot N.I. Bessonov (with Ershov's hand-writted addition "From Karl Efimovich Levitin, July 6, 1983 (Protvino)") Date: 25.04.1983 Original document language: Russian Authors: Alexander S. Kronrod Persons: Karl E. Levitin, N.I. Bessonov
