Lectures Held at the Astrophysics School XII Organized by the European Astrophysics Doctoral Network (EADN) in La Laguna, Tenerife, Spain, 6–17 September 1999

Obervations, Concepts and Interpretations

Proceedings of a Workshop Held at Bielefeld Germany, 10–14 November 1998

Lectures of a Seminar and Workshop held at the Max-Planck-Institut für Physik komplexer Systeme, Dresden, Germany, August 24th to September 18th, 1998

Geometry, Analysis, Numerics