TY  - BOOK
AU  - Wrixon Fred B
TI  - Codes, ciphers, and secret languages
AV  - Z103 
U1  - 652/.8 
PY  - 1989///
CY  - New York
PB  - Distributed by Crown publishers
KW  - Ciphers
KW  - History
KW  - Cryptography
N1  - Bibliography: p. 265-266
ER  -