00281nam a2200097Ia 4500008004100000100001600041245004700057250001900104260004400123650001600167190216s9999||||xx |||||||||||||| ||und||  aIan Sneddon 0aElements Of Partial Differential Equations  aSECOND EDITION  bMcgraw-Hill International Editionc1957  aMathematics