00323    a2200097   4500082001300000100003700013245006500050260005700115300001500172650003800187  a511bOPE  aThe Open University of Sri Lanka  aMathematical methods 11bunit II b sturm - liouville theory  aNawalabThe Open University of Sri Lankac1989g1989  a75p.c29cm  aGeneral principles of Mathematics