TY  - BOOK
AU  - Gardner, Martin 
TI  - Codes, ciphers and secret writing
SN  - 9780486247618
U1  - 001.5436 G171c 
PY  - 1972///
CY  - New York
PB  - Dover Publishers, Inc.
KW  - Cryptography
KW  - Ciphers
ER  -