TY  - BOOK
AU  - Leffingwell, D. 
AU  -  Widrig, D.
TI  - Managing Software Requirements: A Use Case Approach 2/E
SN  - 81-317-1179-8
U1  - 5.1 
PY  - 2007///
CY  - Vidhyanagar
PB  - Pearson
ER  -