00432nam a2200157 a 450000500170000010000160001724500500003326000220008330000100010549000280011569000270014396400230017099700120019399900170020595200520022220251203090719.0  aAyres,Frank  aTheory and problems of differential equations  aMcGraw-Hillc1981  a295p.  aSchaum's outline series  aDifferential equations  bENGLISHcdefg_  a19219 W  c17344d17344  02104070aPUbPUd1998-10-29l0o p19219yBK