pp. 124-118 (1992) Lynden-Bell, D.; Faber, S. M.; Burstein, David; Davies, Roger L.; Dressler, Alan; Terlevich, R. J.; Wegner, Gary. Photometry and Spectroscopy
damtp.cam.ac.uk. [2020-10-11]. (原始内容存档于2009-04-07). Palmer, D. Ask an Astrophysicist: Quantum Gravity and Black Holes. NASA. [2009-03-26]. (原始内容存档于2009-03-28)