... Lecture Notes in PhysicsEditorial Board R. Beig, Wien, AustriaJ. Ehlers, Potsdam, GermanyU. Frisch, Nice, FranceK. Hepp, Z¨urich, SwitzerlandW. Hillebrandt, Garching, Germany D. Imboden, ... A. Weidenm¨uller, Heidelberg, GermanyJ. Wess, M¨unchen, GermanyJ. Zittartz, K¨oln, Germany3BerlinHeidelbergNew YorkBarcelonaHong KongLondonMilanParisSingaporeTokyo...