Mainieri, V. Optical and Interpretative Astronomy, MPI for Extraterrestrial Physics, Max Planck Society;
Koekemoer, A. M., Alexander, D. M., Bauer, F. E., Bergeron, J., Brandt, W. N., Cristiani, S., et al. (2005). Early spitzer detections of Extreme X-ray / Optical sources (EXOs). In A. Merloni, S. Nayakshin, & R. A. Sunyaev (Eds.), Growing black holes: accretion in a cosmological context (pp. 120-125). Berlin: Springer.