Enigma: How Breaking the Code Helped Win World War II

Women Code Breakers: The Best Kept Secret of WWII: True Stories of Female Code Breakers Whose Top-Secret Work Helped Win World War II (Brave Women Who Changed the Course of WWII)

Sekret Machines: War by Peter Levenda (Hardback Book)

The Code Book: The Secret History of Codes and Code-breaking by Simon Singh Book

Spies, Code Breakers, and Secret Agents: A World War II Book... - Roman, Carole