Title: Top secret Ultra
First published: 1980
Subjects: Biography, British Personal narratives, Cryptographers, Cryptography, English Personal narratives, Great Britain, Great Britain. Government Communications Headquarters, History, Personal narratives, British, Personal narratives, English, Secret service, World War, 1939-1945, Cryptographie, Récits personnels britanniques, Guerre mondiale, 1939-1945, Service secret
Places: Great Britain, Grande-Bretagne
People: Peter Calvocoressi