1
by Frahm, Jill
Published 2000
Center for Cryptologic History, National Security Agency

2
by Jeffries, Ian
Published 2006
Routledge

3
by Miyata, Carolina
Published 2006
LID Editorial Empresarial

4
by Brown, Kerry
Published 2010
Chandos Pub.

5
by Dodson, Bill
Published 2011
John Wiley & Sons (Asia)