TY  - GEN
AU  - Sing, Simon
TI  - The code book: the secret history of cods and codebreaking
SN  - 1857028899
PY  - 1999///
CY  - London
PB  - Fourth estate
KW  - CODES
KW  - CODIFICATION
KW  - COMMUNICATION
KW  - DOCUMENTATION
KW  - SYMBOLS
KW  - TECHNOLOGY
ER  -