TY  - BOOK
AU  - Gamma Erich 
AU  - Helm Richard
AU  - Johnson Ralph
AU  - wissides john
TI  - Design Patterns: Elements of Reusable Object - Oriented Software
SN  - 9788131700075
U1  - 005.133 GAM;13 
PY  - 2013///
CY  - New Delhi
PB  - Dorling kindersley Publishing Inc
ER  -