Secret Warriors: The Spies, Scientists and Code Breakers of World War I
Code Breakers: Riveting Reads for Curious Kids (Mega Bites)
Australian Code Breakers
The secret war : the inside story of the code makers and code breakers of World War II
Teachers and code-breakers: the latin Genesis tradition, 430-800
Teachers and Code-Breakers: The Latin Genesis Tradition, 430-800