Kahn, D. (1967). The codebreakers: The story of secret writing (First edition.). The Macmillan Company.
Dyfyniad Arddull ChicagoKahn, David. The Codebreakers: The Story of Secret Writing. First edition. New York: The Macmillan Company, 1967.
Dyfyniad MLAKahn, David. The Codebreakers: The Story of Secret Writing. First edition. The Macmillan Company, 1967.
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