Tolong jelaskan mengenai Kepala dari Abwehr

Brissaud, André. Canaris; the Biography of Admiral Canaris, Chief of German Military Intelligence in the Second World War. New York: Grosset & Dunlap, 1974.

Budiansky, Stephen. Battle of Wits: The Complete Story of Codebreaking in World War II. New York: The Free Press, 2000.

Cruickshank, Charles Greig, and David Barlow. Deception in World War II. Oxford University Press, 1979.

Cubbage, T. L. "The German misapprehensions regarding overlord: Understanding failure in the estimative process." Intelligence and National Security (1987) 2#3 pp: 114-174.

Farago, Ladislas. The Game of the Foxes: The Untold Story of German Espionage in the United States and Great Britain During WWII, David McKay Co. Inc., 1971. .

Herfeldt, Olav. Schwarze Kapelle. Spionage und Widerstand. Die Geschichte der Widerstansgruppe um Admiral Wilhelm Canaris. Augsburg: Weltbild, 1990.

Kitson, Simon. The Hunt for Nazi Spies: Fighting Espionage in Vichy France. Chicago: University of Chicago Press, 2008.

Lerner, K. Lee, and Brenda W. Lerner. Encyclopedia of Espionage, Intelligence, and Security, vol. 1, A-E. New York: Thomson Gale, 2004.

Liddell-Hart, B.H. The German Generals Talk. New York: Quill, 1979, [1948].

O.N.I. Review [Office of Naval Intelligence]. “German Espionage and Sabotage against the United States.” 1, no.3 (Jan. 1946): 33-38. [Declassified]. Full text online and retrievable from: https://web.archive.org/web/20011205033841/http://www.history.navy.mil/faqs/faq114-1.htm (Accessed December 20, 2014).

Schoonover, Thomas. Hitler's Man in Havana: Heinz Luning and Nazi Espionage in Latin America. Lexington: University Press of Kentucky, 2008.

Waller, John H. "The double life of Admiral Canaris." International Journal of Intelligence and Counter Intelligence (1996) 9#3 pp: 271-289.

Waller, John H. The Unseen War in Europe: Espionage and Conspiracy in the Second World War. New York: Random House, 1996.

Gross, Kuno, Michael Rolke & András Zboray, Operation SALAM – László Almásy's most daring Mission in the Desert War, Belleville, München, 2013