Nigel West, Historical dictionary of cold war counterintelligence, Lanham, Md., Scarecrow Press, (ISBN978-0810864634, lire en ligne), p. 155
Darren G. Lilleker, Against the Cold War : the history and political traditions of pro-Sovietism in the British Labour Party 1945–89, London, Tauris, (ISBN1850434719, lire en ligne), p. 9