From the reviews: "This well-organized and constructed work explores ... . There are 11 chapters' beginning with an excellent overview of the four approaches ... . It is, by itself, a very nice review of the topic, and is useful as a guide ... . It is all the more useful because it compares ... in a meaningful context. ... the use of models and simulation, physical and mathematical throughout the work, is impressive ... . This text would be best used in graduate-level courses ... ." (A.G. Greenburg, Computing Reviews, February, 2005)