00269nam a2200109Ia 4500008004100000020001800041100001600059245003700075250001300112260001900125650001500144240827s9999    xx            000 0 und d  a9788121909686  aP. K. Gupta 0aProblems In Operations Research   a4th Rev.  bS.Chand c2021  aManagement