Britain's best kept secret : Ultra's base at Bletchley Park /
Enever, Ted.
[Stroud] : Bramley,
1999, c1994.
First published: Stroud : Sutton, 1994.
Great Britain. Government Communications Headquarters
World War, 1939-1945
World War, 1939-1945
World War, 1939-1945
World War, 1939-1945