APA (7th ed.) Citation

Pennycook, A. (1980). Codes and ciphers. McKay.

Chicago Style (17th ed.) Citation

Pennycook, Andrew. Codes and Ciphers. New York: McKay, 1980.

MLA (9th ed.) Citation

Pennycook, Andrew. Codes and Ciphers. McKay, 1980.

Warning: These citations may not always be 100% accurate.