The chairman of the KGB was the head of the Committee for State Security (KGB), the main security agency of the Soviet Union in 1954–1991. He was assisted by one or two first deputy chairmen, and four to six deputy chairmen. He was also the head of the Collegium of the KGB—which consisted of the chairman, deputy chairmen, directorate chiefs, and one or two republic-level KGB organization chairmen—who affected key policy decisions.
In 1934–1943 the Soviet State Security agency was part of the People's Commissariat for Internal Affairs (NKVD) as the Main Directorate of State Security (GUGB). The director of the GUGB was the first deputy of the People's Commissar of Interior.
Vadim J. Birstein. The Perversion Of Knowledge: The True Story of Soviet Science. Westview Press (2004) ISBN0-8133-4280-5 (describes a secret KGB lab engaged in development and testing of poisons)
John Dziak, Chekisty: A History of the KGB, Lexington Books (1988) ISBN978-0-669-10258-1
Бережков, Василий Иванович (2004). Руководители Ленинградского управления КГБ : 1954–1991. Санкт-Петербург: Выбор, 2004. ISBN5-93518-035-9 (in Russian)