00279nam a22001097a 4500020001800000040000900018082001500027100002600042245003600068260003800104650002700142  a9788120336384  cNUST  a515.35 BIS  aBiswal, Purna Chandra  aOrdinary Differential Equations  aNew Delhi:bPHI LEARNING, c2008.  aDifferential Equations