Title: Code-Breaker
Subjects: World war, 1939-1945, ireland, World war, 1939-1945, cryptography, World war, 1939-1945, secret service, World War, 1939-1945, Cryptography, Cryptographers, Biography, Librarians, Secret service, World War (1939-1945) fast (OCoLC)fst01180924 (uri) http://id.worldcat.org/fast/fst01180924