General KGB meets world's finest cryptologic historian
From a book https://books.google.sk/books?id=35ClAgAAQBAJ&pg=PA292#v=onepage&q&f=false And from an original article from the magazine Cryptologia: Kahn, David(1998) 'SOVIET COMINT IN THE COLD WAR', Cryptologia, 22: 1, 1 — 24: