APA

Pratt F., Lamb G. C. C. & American Cryptogram Association. (1942). Secret and urgent: the story of codes and ciphers. Garden City, N.Y: Blue Ribbon Books.

Chicago

Pratt Fletcher, Lamb George C Collection and American Cryptogram Association. 1942. Secret and urgent: the story of codes and ciphers. Garden City, N.Y: Blue Ribbon Books.

Harvard

Pratt F., Lamb G. C. C. and American Cryptogram Association. (1942). Secret and urgent: the story of codes and ciphers. Garden City, N.Y: Blue Ribbon Books.

MLA

Pratt Fletcher, Lamb George C Collection and American Cryptogram Association. Secret and urgent: the story of codes and ciphers. Garden City, N.Y: Blue Ribbon Books. 1942.