Gallehawk, J. (2011). How the ultra secret was nearly revealed: [This booklet, which is based upon a Bletchley Park Lecture given in January 1998, describes three situations that came very close to revealing the Allies most precious secret in World War II, the ULTRA intelligence based on the decryption of the German Enigma cipher messages] (New ed.). Bletchley Park Trust.
Chicago-Zitierstil (17. Ausg.)Gallehawk, John. How the Ultra Secret Was Nearly Revealed: [This Booklet, Which Is Based upon a Bletchley Park Lecture Given in January 1998, Describes Three Situations That Came Very Close to Revealing the Allies Most Precious Secret in World War II, the ULTRA Intelligence Based on the Decryption of the German Enigma Cipher Messages]. New ed. Milton Keynes: Bletchley Park Trust, 2011.
MLA-Zitierstil (9. Ausg.)Gallehawk, John. How the Ultra Secret Was Nearly Revealed: [This Booklet, Which Is Based upon a Bletchley Park Lecture Given in January 1998, Describes Three Situations That Came Very Close to Revealing the Allies Most Precious Secret in World War II, the ULTRA Intelligence Based on the Decryption of the German Enigma Cipher Messages]. New ed. Bletchley Park Trust, 2011.