Randall K. Nichols. Classical cryptography course.
J.H. Loxton. Number theory and cryptography.
Dominic Welsh. Codes and cryptography
Alan G. Konheim. Cryptography, a primer.
David Kahn. Codebreakers : the story of secret writing AMAZING book!
William F. Friedman and Lambros D. Callimahos. Military cryptanalytics pt.1 v.2 Aegean Press, 1985
William F. Friedman and Lambros D. Callimahos. Military cryptanalytics pt.1 v.1 Aegean Press, 1985
William F. Friedman and Lambros D. Callimahos. Military cryptanalytics pt.2 v.1 Aegean Press, 1985
William F. Friedman and Lambros D. Callimahos. Military cryptanalytics pt.2 v.2 Aegean Press, 1985
Cryptography; the science of secret writing Sarnoff/Ruffins. The Code and Cipher Book. New York: Charles Scribner's Sons, 1975.