Physics of Active Galactic Nuclei Proceedings of the International Conference, Heidelberg, 3–7 June 1991 Duschl Wolfgang J. Heftet / 2012 / Engelsk
Variability of Active Galaxies Proceedings of a Workshop of the Sonderforschungsbereich 328 Held at Heidelberg, Germany, 3–5 September 1990 Duschl Wolfgang J. Heftet / 2014 / Engelsk
