00353nam a2200133 a 450000500170000002000180001708200170003510000160005224500350006825000120010326000450011530000230016050000360018320251203111954.0  a9788184892130  a515.353bJOH  aJohn, Fritz  aPartial differential equations  a4th ed.  aUnited States of AmericabSpringerc2009  ax,249p.c20cm.bPB  aincludes bibliography and index