"This book covers some of the main aspects of nonlinear analysis. It
concentrates on stressing the fundamental ideas instead of elaborating
on the intricacies of the more esoteric ones...it encompass[es] many
methods of dynamical systems in quite simple and original settings. I
recommend this book to anyone interested in the main and essential
concepts of nonlinear analysis as well as the relevant methodologies and
applications." --MATHEMATICAL REVIEWS