Poland’s Enigma Code Breakers

Wesolkowski, Slawo. The Invention of Enigma and how the Polish Broke it before the Start of WWII. (Waterloo: The University of Waterloo), 2. Ethw.org (Accessed September 20, 2019) https://ethw.org/w/images/b/bb/Wesolkowski.pdf
Wesolkowski. The Invention of Enigma, 3 -4. (Accessed September 20, 2019) https://ethw.org/w/images/b/bb/Wesolkowski.pdf
Ibid. 4.
Wesolkowski. The Invention of Enigma, 4 -5.. (Accessed September 20, 2019) https://ethw.org/w/images/b/bb/Wesolkowski.pdf. Marian Rejewski. “How Polish Mathematicians Deciphered the Enigma.” Annals of the History of Computing Vol. 3 (1981): 213 - 234. (Accessed September 20, 2019) https://pdfs.semanticscholar.org/1962/111befaaf868b478f1024c2cd45d003cdf7a.pdf
“A Conversation with Marian Rejewski.” In Enigma: How the German Cipher was Broken, and How it was read by the Allies in World War Two. Edited by Władysław Kozaczuk and Christopher Kasparek. (Frederick: University Publications of America, 1984), 229 - 240.
Enigma, the French, the Poles and the British 1931 - 1940. Revue belge de Philologie et d'Histoire (2004): 449 - 466. Persee.fr. (Accessed September 20, 2019) https://www.persee.fr/doc/rbph_0035-0818_2004_num_82_1_4836
Rejewski. “How Polish Mathematicians Deciphered the Enigma,” 220.
Enigma Message Procedures.” Cipher Machines and Cryptology. (Accessed September 20, 2019) http://users.telenet.be/d.rijmenants/en/enigmaproc.htm
Marian Rejewski. “Summary of Our Methods for Reconstructing ENIGMA and Reconstructing Daily Keys, and of German Efforts to Frustrate those Methods.” In Kozaczuk and Kasparek. Enigma, 242.