Alan (1 January 2006). Onscreen and Undercover: The Ultimate Book of Movie Espionage. Greenwood Publishing Group. p. 128. ISBN 978-0-275-99281-1. https://books
John Earl Haynes and Harvey Klehr. In Denial: Historians, Communism, and Espionage. Encounter Books, 2003. ISBN 1-893554-72-4 p. 22 ^ Aleksandr Shelepin's