TY  - BOOK
AU  - Butler,William S.
AU  - Keeney,L.Douglas
TI  - Secret messages: concealment, codes, and other types of ingenious communication 
SN  - 0684869985
AV  - Z103 .B88 2001
U1  - 652/.8 21
PY  - 2001///
CY  - New York
PB  - Simon & Schuster
KW  - Ciphers
KW  - Cryptography
N1  - Includes bibliographical references (p. 179-181) and index
ER  -