APA (7th ed.) Citation

Smith, L. D. (1971). Cryptography: The science of secret writing. Dover Publications.

Chicago Style (17th ed.) Citation

Smith, Laurence Dwight. Cryptography: The Science of Secret Writing. New York: Dover Publications, 1971.

MLA (9th ed.) Citation

Smith, Laurence Dwight. Cryptography: The Science of Secret Writing. Dover Publications, 1971.

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