Notes
- Benson , Robert L. 1977 . ‘The Origin of U.S.‐British Communications Intelligence Cooperation (1940–41)’ . Cryptologic Spectrum 1/4 , Fall : 5
- Smith , Bradley F. 1993 . The Ultra‐Magic Deals and the Most Secret Special Relationship, 1940–1946 , 43 – 4 . Novato , CA : Presidio Press .
- Hinsley , F.H. 1981 . British Intelligence in the Second World War: Its Influence on Strategy and Operations , Vol. II , 41 New York : CUP .
- Benson , Robert Louis . 1997 . A History of U.S. Communications Intelligence during World War II: Policy and Administration , Vol.8 , 102 – 8 . United States Cryptologic History, Series IV, World War II . (Center for Cryptologic History, National Security Agency
- Putney , Diane T. , ed. 1987 . Ultra and the Army Air Forces in World War II , 84 Washington DC : Office of the Air Force .