matrix operations (e.g., MATLAB). To help with physical insight, there are over 80 gures, numerous examples and exercises distributed throughout the book. There are, perhaps 50 books on QT that are available today, and most practitioners have several of them on their shelves. This book would be a good addition, as well as a good supplement to another text. This second edition has been updated throughout including a new chapter on Semi Markov Processes and new material on matrix representations of distributions and Power-tailed distribution. Lester Lipsky is a Professor in the Department of Computer Science and Engineering at the University of Connecticut.