Doeleman, Sheperd (21 Haziran 2009). "Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole". Astro2010: The Astronomy and Astrophysics Decadal Survey, Science White Papers. 2010: 68. arXiv:0906.3899 $2. Bibcode:2009astro2010S..68D.
The Event Horizon Telescope Collaboration (10 Nisan 2019). "First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole". The Astrophysical Journal Letters. 875 (1): L1. arXiv:1906.11238 $2. Bibcode:2019ApJ...875L...1E. doi:10.3847/2041-8213/ab0ec7.
The Event Horizon Telescope Collaboration (10 Nisan 2019). "First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole". The Astrophysical Journal Letters. 875 (1): L1. arXiv:1906.11238 $2. Bibcode:2019ApJ...875L...1E. doi:10.3847/2041-8213/ab0ec7.
Doeleman, Sheperd (21 Haziran 2009). "Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole". Astro2010: The Astronomy and Astrophysics Decadal Survey, Science White Papers. 2010: 68. arXiv:0906.3899 $2. Bibcode:2009astro2010S..68D.
The Event Horizon Telescope Collaboration (10 Nisan 2019). "First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole". The Astrophysical Journal Letters. 875 (1): L1. arXiv:1906.11238 $2. Bibcode:2019ApJ...875L...1E. doi:10.3847/2041-8213/ab0ec7.