"Definitely the best textbook for a second course in probability now available. Written with excruciating lucidity, and with an excellent choice of exercises." --Gian-Carlo Rota "A very fine textbook which will become popular among students as well as among professors preparing an introductory course on stochastic processes." --Int'le Math. Nachrichten "A splendid book to bring home the value and importance of stochastic processes. Highly recommended." --Choice