Title: The Battle of the Atlantic and signals intelligence
Subjects: Campaigns, Submarine, World War, 1939-1945, Cryptography, Naval operations, German Naval operations, Military intelligence, World war, 1939-1945, cryptography, World war, 1939-1945, military intelligence, World war, 1939-1945, naval operations, submarine, World war, 1939-1945, aerial operations, german, World war, 1939-1945, campaigns, atlantic ocean
Places: Atlantic Ocean