Francisco M. Fernandez
"""Professor Fernandez [has been] active in the field of quantum mechanical perturbation theory for many years. … [T]he book has been prepared and written with-and to-the author's undisguised delight, offering a specific blend of the theory and computations. … The book informs the reader, in an admirably compact and still unbelievably digestible text, about virtually all the basic concepts … ."" - Zentralblatt MATH, Vol. 1048 ""… summarizes in detail a wide variety of techniques used in perturbation theory that were developed for particular problems. To make the methods easily comparable, they are applied to the same models. Some of these models have exact solutions, so that improvement in the perturbation series and their limitations become clear…author intentionally avoids problems that require numerical computation and tries to keep the mathematics as simple as possible in order to concentrate the reader's attention on the ideas underlying each method…offers an invaluable source of ideas for theoreticians applying perturbation methods to various problems in chemistry and physics…it can also be used for teaching undergraduate and graduate courses…"" -Journal of the American Chemical Society, Vol. 123, No. 26 ""…a very substantial presentation of perturbation theory in quantum mechanics, much of which is based on the publication of the author and his coworkers…the book is clearly an important reference work in the field, and the author has completed a laudable task."" -Mathematical Reviews, Issue 2002"