Walsh, Jonelle L.; Barth, Aaron J.; Ho, Luis C.; Sarzi, Marc (June 2013). ”The M87 Black Hole Mass from Gas-dynamical Models of Space Telescope Imaging Spectrograph Observations”. The Astrophysical Journal 770 (2): sid. 86. doi:10.1088/0004-637X/770/2/86. Bibcode: 2013ApJ...770...86W.
Walsh, Jonelle L.; Barth, Aaron J.; Ho, Luis C.; Sarzi, Marc (June 2013). ”The M87 Black Hole Mass from Gas-dynamical Models of Space Telescope Imaging Spectrograph Observations”. The Astrophysical Journal 770 (2): sid. 86. doi:10.1088/0004-637X/770/2/86. Bibcode: 2013ApJ...770...86W.