"This booklet, which is based upon a Bletchley Park Lecture, ia an extended version of the origins of the first real break into the Enigma by the Poles and then further breaks at Bletchley Park."
"January 2011."
"In association with Royal Holloway University of London."
Title from cover.
The first break into German Enigma at Bletchley Park by Brian Oakley. ISBN 9781906723149. Published by Bletchley Park Trust in 2011. Publication and catalogue information, links to buy online and reader comments.