Review of The Triumph of Zygalski's Sheets: The Polish Enigma in the Early 1940 by Zdzisław J. Kapera: Kapera, Zdzisław J. The Triumph of Zygalski's Sheets: The Polish Enigma in the Early 1940. The Enigma Press, Mogilany, Poland, 2015. 221 pages, A5 cardcover. ISBN 978-83-86110-79-7. Issue 3 (4th May 2017) - Christensen, Chris