First comes an extremaly negative review by Imre Leader.
"... but I am afraid that I would not recommend it to any student, or to anyone wishing to learn about extremal combinatorics"
I guess that this negative impression came from completely ignoring all my "excuses" made already in the subtitle, and in the preface: this was not meant to be an "encyclopedia book" in the extremal combinatorics itself. This was rather meant to be a "combinatorial toolbox" for computer scientists. But the critics of Imre was very useful when preparing the 2nd edition of the book.
Here are reviews I've extracted from Springer's site:
"This monograph deals with problems of the following type: ‘If a collection of finite objects … satisfies certain restrictions, how large or how small can it be?’ The text is self-contained and assumes no special knowledge (only a standard mathematical background). Moreover, its 29 chapters – ‘each devoted to a particular proof technique’ – are (almost) independent. Because of this modularity, its style … and the character of its subject, this book can also be browsed and read for (mathematical) pleasure." (P. Schmitt, Monatshefte für Mathematik, Vol. 141 (1), 2004)
"The book is structured as a collection of short, largely independent chapters, each dedicated to a specific proof technique. … The book is broad in scope and gives equal space to the classical counting techniques and to more recent methods. … I used the book to teach a small group of graduate students. It was a rewarding experience. … The material was interesting, diverse, and challenging. … this is a book I heartily recommend to anyone wishing to learn or teach combinatorics." (Jeannette C. M. Janssen, SIAM Review, Vol. 26 (1), 2004)
"The author has covered a huge amount of ground in this book. … Each topic is covered in a way that takes the reader from the start right up to the most recent results in the area. … the book is clearly a ‘labour of love’. The author’s enthusiasm for the subject shines through page after page: it is hard not to feel his excitement as one reads what he has written." (Imre Leader, Combinatorics, Probability and Computing, Vol. 13, 2004)
"A text suitable for advanced undergraduate or graduate students. It begins with basics, inclusion-exclusion, pigeonhole, systems of distinct representatives. Substantial space is devoted to the more modern linear algebra and probabilistic methods. Algorithmic aspects permeate the book, making it suitable for a computer science, or joint math/computer science course. There are numerous exercises." (J. Spencer, Mathematical Reviews, Issue 2003 g)
"Extremal Combinatorics is a part of finite mathematics … . The present book collects many different aspects of the field. It is wider than deep having 29 relatively short and independent chapters. These properties make the book accessible to a broad readership. … this volume also contains a large number of well chosen exercises of various range of difficulty. There is a useful home page edited by the author … . We warmly recommend this well-written and nicely edited book to anybody with combinatorial interest." (János Barát, Acta Scientiarum Mathematicarum, Vol. 68, 2002)
"This book presents several important parts of combinatorics with emphasis to methods for solving extremal problems. Some interesting applications in theoretical computer science are included. … As written in the preface, the text is indeed self-contained and the chapters are almost independent. More than 300 exercises … are included. The presentation is clear and sound. The book is not only valuable for students and teachers, but also for researchers working in discrete mathematics or theoretical computer science." (Konrad Engel, Zentralblatt MATH, Vol. 978, 2002)
"A collection of gems from the field of extremal combinatorics, written in the informal but thorough style of George Polya. I very much enjoy browsing this book, especially at night, when I 'm looking for a digestible morsel to chew on before falling asleep. Like Polya, his writing style is both upbeat, lean and enthusiastic. The author doesn't dwell too much on any single problem and covers a lot ground for a single book, using concrete problems to illustrate a particular subject. The book reads as if the author is speaking directly to you. I am professional programmer with a math background who very much recommends this book to a programmer looking to get a feel for the subject of combinatorics from a more than introductory point of view. I would have given 5 stars, but the editing is sloppy. Also, don't expect to start cutting code tomorrow. The book is much more a math book than computer science book." (Review by John Scott at Amazon, entitled as "Polya Lives," December 31, 2010).