Kahn, D. (1967). The codebreakers: : the story of secret writing. MacMillan.
Cita Chicago Style (17a ed.)Kahn, David. The Codebreakers: : The Story of Secret Writing. New York: MacMillan, 1967.
Cita MLA (9a ed.)Kahn, David. The Codebreakers: : The Story of Secret Writing. MacMillan, 1967.
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