Published: June 1986
It begins at an elementary level and ends at the frontiers of current research, and the journey is enlivened by readable exposition, helpful motivation, interesting historical background and elegant proofs... a truly notable achievement...
Bulletin of the London Mathematical Society
Everything is developed with splendid clarity, organized in a masterful way and written in an excellent style, sometimes exciting, sometimes humorous, always maintaining a lively dialogue with the reader. This beautiful book provides a comprehensive treatment of the subject, leading up to the frontiers of current research.