00297nam a2200109 a 450000500170000008200220001710000220003924500630006126000320012430000160015670000150017220251203091734.0  a658.4034,bD, gup  aGupta, Prem Kumar  aProblems in operations research (principles and solutions)  aDelhibS. Chand & Co.c1991  a1078p, 22cm  aHira, D.S.