Brightman, M. High Energy Astrophysics, MPI for Extraterrestrial Physics, Max Planck Society;
Ricci, C., Paltani, S., Awaki, H., Petrucci, P.-O., Ueda, Y., & Brightman, M. (2013). Luminosity-dependent unification of active galactic nuclei and the X-ray Baldwin effect. Astronomy & Astrophysics, 553: A29, pp. 1-9. doi:10.1051/0004-6361/201220324.