00355nam a22001337a 4500020001800000040000900018082001600027100002500043110003200068245003000100250001900130260004200149650003000191  a9788126554270  cNUST  a005.43bSIL  aSilberschatz Abraham  aGlavin Peter B., Gagne Gerg  aOperating System Concepts  aNineth Edition  aNew Dehli:bJohn Wiley & Sons,c2016.  aOperating System Concepts