This book is a useful and accessible introduction to symmetry principles in particle physics. Concepts of group theory are clearly explained and their applications to subnuclear physics brought up to date. The book begins with introductions to both the types of symmetries known in physics and to group theory and representation theory. Successive chapters deal with the symmetric groups and their Young diagrams, braid groups, Lie groups and algebras, Cartan's classification of semi-simple groups, and the Lie groups most used in physics are treated in detail. Gauge groups are discussed, and...