The book covers both theory and observations. Theoretical models presented in analytical and phenomenological forms that are tailored to practical applications. These are welded together with empirical data extending from the early pioneering observations to the most recent state-of-the-art data.

This new edition of the book is updated and contains a significant amount of new material throughout as well as four new chapters and 48 problems with solutions. Most problems make use of original papers containing fundamental results. This way, the original paper, often based on complex theory, turns into a convenient tool for practical use and quantitative analysis.