Partial Differential Equations (4^th Ed., 4th ed. 1982. Softcover reprint of the original 4th ed. 1982) Applied Mathematical Sciences Series, Vol. 1

?An excellent second-reading text.  Should be accessible to any mathematician.  Highly recommended.? ? The Mathematical Gazette

?An excellent text upon which to build and introduction to partial differential equations at the graduate level.  In addition?recommended for the nonspecialist.? ? American Mathematical Monthly

Partial Differential Equations is a very well accepted introduction to the subject.  In it, the author identifies the significant aspects of the theory and explores them with a limited amount of machinery from mathematical analysis.  Now, in this fourth edition, the book has again been updated with an additional chapter on Lewy?s example of a linear equation with solutions.