TY  - BOOK
AU  - Sommerville, Ian
AU  - Sawyer, Pete
TI  - Requirements engineering: a good practice guide 
SN  - 0-471-97444-7
AV  - QA 76.76 .S66 1997
PY  - 1997///
CY  - New york
PB  - John wiley& sons
KW  - System modeling
KW  - Engineering
KW  - Requirements
ER  -