From the reviews: "The aim of the book is to present "the systematic development of the general theory of second order quasilinear elliptic equations and of the linear theory required in the process." The book is divided into two parts. The first (ch. 2 - 8) is devoted to the linear theory, the second (ch. 9 - 15( to the theory of quasi-linear partial differential equations. These 14 chapters are preceded by an Introduction (ch. 1) which expounds the main ideas and can serve as a guide to the book. The authors have succeeded admirably in their aims; the book is a real pleasure to read." Mathematical Reviews This new printing contains numerous corrections and revisions.