TY  - BOOK
AU  - Leffingwell, Dean
AU  - Widrig, Don
TI  - Managing Software Requirements: A Use Case Approach
T2  - The Addison-Wesley Object Technology Series
SN  - 8129703912
U1  - 005.3 
PY  - 2003///
CY  - Delhi
PB  - Pearson Education
ER  -