'Several features of this book are original. First of all: the topic … Next, thanks to the unique style of the author, this book offers a pleasant reading; a number of nice jokes enable the reader to have a good time while learning high level serious mathematic … This book includes a large number of statements, proofs, ideas, problem which will be of great value for the specialists; but it should interest also any mathematician, including students, who wish to expand their knowledge and see a superb example of a topic having an surprising number of different applications in several directions.' Bulletin of the European Mathematical Society