• Fermat's Enigma : The Epic Quest to Solve the World's Greatest Mathematical Problem by Simon Singh, John Lynch / Published 1998 / Bantam Books

• Code Breaking : A History and Exploration by Rudolf Kippenhahn, Ewald Osers / Published 1999 / Overlook Press

• Alan Turing: The Enigma by Andrew Hodges, Douglas Hofstadter / Published 2000 / Boston: Walker & Co

• Crypto : How the Code Rebels Beat the Government -- Saving Privacy in the Digital Age by Steven Levy / Published 2001 / Viking Press

• Enigma : How the German Cipher Was Broken, and How it Was Read by the Allies in WWII by Wladyslaw Kozaczuk / Hardcover / Published Ed. and trans. by Christopher Kasperek, Frederick, MD: University Publications of America, 1984

• Seizing the Enigma: The Race to Break the German U-Boat Codes, 1939-1943 by David Kahn / Published 1991 / Boston: Houghton Mifflin

• The Codebreakers : The Story of Secret Writing by David Kahn / Hardcover / Published 1983

• Codebreakers : The Inside Story of Bletchley Park by F. H. Hinsley (Editor), Alan Stripp (Editor) / Paperback / Published 1994

• Enigma: The Battle for the Code by Hugh Sebag-Montefiore / Hardcover /
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• The Codebreakers; The Comprehensive History of Secret Communication from Ancient Times to the Internet by David Kahn / Hardcover, 1181 pages / Published by Scribner 1996

• "Geheimoperation Wicher" - Polnische Mathematiker knacken den deutschen Funkschlüssel >>Enigma<< by Wladyslaw Kozaczuk / Hardcover / Published by Karl Müller Verlag, Erlangen, ISBN 3-86070-803-1 Preface by the German Publisher Prof. Dr. Jürgen Rohwer - präses des Arbeitskreises für Wehrforschung.

• Enigma, ou la plus grande enigme de la guerre 1939-1945, Gustave Bertrand, Paris - Plon, 1973.

• The Enigma War by Jozef Garlinski / Published 1983

• The Code Book - The Evolution of Secrecy from Mary Queen Scots to Quantum Cryptography by Simon Singh / Published by Doubleday, New York, 1999, ISBN 0-385-49531-5, 402 pp

• Alan Turing : The Enigma by Andrew Hodges / Published 1984 / New York, Simon and Schuster

• On making and breaking codes, Part I, Scientific American, October 1988

• Breaking codes was the couple's lifetime career, Smithsonian, volume 18, p. 128ff.

• Szyfr Enigmy. Metody zlamania by Krzysztof Gaj; Warszawa, Wydawnictwo Komunikacji i Lacznosci, 1989

• The Enigma: The Secret Weapon of World War II Polish American Journal / October 1990

• Cryptologia A quarterly journal devoted to all aspects of cryptology.

Other essential literature on the Subject: Cryptography

• Applied Cryptography : Protocols, Algorithms, and Source Code in C by Bruce Schneier / Hardcover / Published 1996
• Codes and Ciphers : An A to Z of Covert Communication, from the Clay Tablet to the Microdot by Fred B. Wrixon / Paperback, 260 pages / Published by MacMillan General 1992
• Codes and Cryptography by Dominic Welsh / Paperback / Published 1988
• Combined Fleet Decoded : The Secret History of American Intelligence and the Japanese Navy in World War II by John Prados / Hardcover / Published 1995
• Contemporary Cryptology : The Science of Information Integrity by Gustavus J. Simmons (Editor) / Hardcover / Published 1992
• Cryptography : Theory and Practice (Discrete Mathematics and Its Applications) by Douglas R. Stinson / Hardcover / Published 1995
• Cryptography's Role in Securing the Information Society by Kenneth W. Dam and Herbert S. Lin, Editors / Paperback / Published 1996
• Decrypted Secrets : Methods and Maxims of Cryptology by Friedrich L. Bauer / Hardcover / Published 1997
• Disappearing Cryptography : Being and Nothingness on the Net by Peter Wayner / Paperback / Published 1996
• Encyclopedia of Cryptology by David E. Newton / Hardcover / Published 1997
• Handbook of Applied Cryptography (CRC Press Series on Discrete Mathematics and Its Applications) by Alfred J. Menezes, et al / Hardcover / Published 1996
• Introduction to Cryptolology and PC Security by Brian Beckett / Hardcover / Published 1997
• Secret Code Breaker II - A Cryptanalyst's Handbook by Robert Reynard / Paperback / Published 1997