Aschenbach, B. High Energy Astrophysics, MPI for Extraterrestrial Physics, Max Planck Society;
Aschenbach, B. (2004). Measuring mass and angular momentum of black holes with high-frequency quasi-periodic oscillations. Astronomy & Astrophysics, 425(3), 1075-1082. doi:10.1051/0004-6361:20041412.