Resonant absorption troughs in the gamma-ray spectra of QSO See section 4.2 http://www.aanda.org/index.php?option=article&access=standard&Itemid=129&url=/articles/aa/full/2005/24/aa1815-04/aa1815-04.html
J. R. Webb; M. T. Carini; S. Clements; S. Fajardo; P. P. Gombola; R. J. Leacock; et al. (1990). "The 1987-1990 optical outburst of the OVV quasar 3C 279". Astronomical Journal. 100: 1452–1456. Bibcode:1990AJ....100.1452W. doi:10.1086/115609. /wiki/Bibcode_(identifier)
J. R. Webb; M. T. Carini; S. Clements; S. Fajardo; P. P. Gombola; R. J. Leacock; et al. (1990). "The 1987-1990 optical outburst of the OVV quasar 3C 279". Astronomical Journal. 100: 1452–1456. Bibcode:1990AJ....100.1452W. doi:10.1086/115609. /wiki/Bibcode_(identifier)
APOD: December 26, 1998 - Gamma Ray Quasar https://antwrp.gsfc.nasa.gov/apod/ap981226.html
The Event Horizon Telescope Collaboration (10 April 2019). "First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole". The Astrophysical Journal. 875 (1): 22. arXiv:1906.11243. doi:10.3847/2041-8213/ab1141. hdl:10150/633754. https://doi.org/10.3847%2F2041-8213%2Fab1141
Apparent superluminal motion http://www.spacetimetravel.org/bewegung/bewegung4.html
Singh, K. K.; Meintjes, P. J.; Ramamonjisoa, F. A. (2020). "Understanding the giant gamma-ray outburst on June 16, 2015 from the blazar 3C 279". Astrophysics and Space Science. 365 (2): 33. arXiv:2002.04965. Bibcode:2020Ap&SS.365...33S. doi:10.1007/s10509-020-3746-2. S2CID 254265537. /wiki/ArXiv_(identifier)
Kim, Jae-Young; et al. (EHT) (April 7, 2020). "Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution" (PDF). Astronomy & Astrophysics. 640: A69. Bibcode:2020A&A...640A..69K. doi:10.1051/0004-6361/202037493. Retrieved April 8, 2020. https://www.aanda.org/articles/aa/pdf/forth/aa37493-20.pdf