TY  - BOOK
AU  - Beatty,Ken
TI  - Secret codes
T2  - Penguin readers
SN  - 1405852224 
U1  - 428.6 22
PY  - 2007///
CY  - Harlow, England
PB  - Pearson Education Limited
KW  - Readers
KW  - Cryptography
KW  - BUEsh
KW  - June2011
KW  - HHUUEENN
KW  - Reading book
ER  -