00500nam a2200193 a 450000500170000002000180001708200180003510000250005310000150007824500610009325000110015426000290016530000240019450000440021860000080026263000240027085600060029485600060030020251219155902.0  a9788121909686  a658.4034bGUP  aGupta, Prem Kumard_  aHira , D.S  aProblems in operation researchbprinciples and solutions  arev.ed  aNew DelhibS Chandc2020  a1293 p.c22 cm.cPB  a1st edition in 1991 and reprint in 2020  bc_  aOperations research  f_  a_