`The book is well written. It can be recommended to chemists, engineers and physicists who wish to learn a rigorous mathematical foundation of their problems.' Mathematical Reviews (1986) `It is admirable, how the authors managed to display such a wealth of material including the necessary prerequisites of functional analysis and measure theory, so that a reader with a knowledge of only the fundamentals of higher mathematics can follow the exposition. A welcome addition to the literature!' Zentralblatt für Mathematik