Doeleman, Sheperd (2009년 6월 21일). “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. Bibcode:2009astro2010S..68D.
Doeleman, Sheperd (2009년 6월 21일). “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. Bibcode:2009astro2010S..68D.