The Scotland Yard Puzzle Book: Test Your Inner Detective by Solving Some of the World's Most Difficult Cases Paperback $18.99
The Secret Lives of Codebreakers: The Men and Women Who Cracked the Enigma Code at Bletchley Park Paperback $24.00
The Hidden History of Code-Breaking: The Secret World of Cyphers, Uncrackable Codes, and Elusive Encryptions Hardcover $29.95
