Title: Thirty secret years
First published: 2007
Subjects: Cryptography, World War, 1914-1918, Secret service, World War, 1939-1945, Cryptographers, Biography, History, Officials and employees
Places: Great Britain, Scotland
People: Alastair Guthrie Denniston (1881-1941)
Time periods: 20th century
LC classification: Z103.4.G7 D46 2007