Grupe, D. High Energy Astrophysics, MPI for Extraterrestrial Physics, Max Planck Society;
Grupe, D., & Wills, B. J. (2002). X-ray polarimetry of AGN with XEUS. In G. Hasinger, T. Boller, & A. N. Parmar (Eds.), Proceedings of the International Workshop XEUS - Studying the Evolution of the Hot Universe (pp. 259-260). Garching: Max-Planck-Institut für extraterrestrische Physik.