From the reviews:“This book should be of considerable interest for students and scholars working on functional equations. … the chapters treat in detail classical subjects such as Cauchy trigonometric and quadratic functional equations and present most recent results from the literature. … a comprehensive bibliography of more than 800 titles conclude this interesting book.” (Gian Luigi Forti, Mathematical Reviews, Issue 2010 e)“In seventeen chapters and on the order of 800 pages (yikes!) we are presented with what must surely be something of an encyclopaedic treatment of the according topics. … To be sure, Kannappan’s book presents us with a most useful vade mecum for many mathematicians (not just arithmeticians) as well as various users of mathematics … .” (Michael Berg, The Mathematical Association of America, December, 2009)“This is a comprehensive, almost encyclopedic treatment of most of the classical topics of functional equations. … the author gives references to books and survey articles. So if you want information about a topic in the field of functional equations and its history, this monograph is an obvious and good place to consult for classical results, applications and references.” (Henrik Stetkaer, Zentralblatt MATH, Vol. 1178, 2010)“This is an encyclopaedic treatment of functional equations and inequalities by one of the leading experts in the field. … The book will be of interest not only to mathematicians but also to scientists and engineers interested in certain aspects of the field. It also contains a very substantial list of references with more than 800 entries.” (M. Kunzinger, Monatshefte für Mathematik, Vol. 163 (1), May, 2011)“A laudable aim of the book is to provide scientists with some selected results of functional equations which can be useful in their subject areas. … The well-written text is a careful … exposition of functional equations, and istherefore very useful for anyone who wishes to study this very interesting and growing area of mathematics. With 841 research items being listed in the bibliography, and separate indices for authors and subjects, the book is also a useful source for reference even for the specialists.” (Peter Shiu, The Mathematical Gazette, Vol. 95 (532), March, 2011)
