Eisenhauer, F.; Schdel, R.; Genzel, R.; Ott, T.; Tecza, M.; Abuter, R.; Eckart, A.; Alexander, T. (2003), "A Geometric Determination of the Distance to the Galactic Center", The Astrophysical Journal, vol. 597 no. 2, pp. L121, arXiv:astro-ph/0306220, Bibcode:2003ApJ...597L.121E, doi:10.1086/380188
Eisenhauer, F.; Schdel, R.; Genzel, R.; Ott, T.; Tecza, M.; Abuter, R.; Eckart, A.; Alexander, T. (2003), "A Geometric Determination of the Distance to the Galactic Center", The Astrophysical Journal, vol. 597 no. 2, pp. L121, arXiv:astro-ph/0306220, Bibcode:2003ApJ...597L.121E, doi:10.1086/380188
McNamara, D. H.; Madsen, J. B.; Barnes, J.; Ericksen, B. F. (2000), "The Distance to the Galactic Center", Publications of the Astronomical Society of the Pacific, vol. 112 no. 768, p. 202, Bibcode:2000PASP..112..202M, doi:10.1086/316512
Eisenhauer, F.; Schdel, R.; Genzel, R.; Ott, T.; Tecza, M.; Abuter, R.; Eckart, A.; Alexander, T. (2003), "A Geometric Determination of the Distance to the Galactic Center", The Astrophysical Journal, vol. 597 no. 2, pp. L121, arXiv:astro-ph/0306220, Bibcode:2003ApJ...597L.121E, doi:10.1086/380188
McNamara, D. H.; Madsen, J. B.; Barnes, J.; Ericksen, B. F. (2000), "The Distance to the Galactic Center", Publications of the Astronomical Society of the Pacific, vol. 112 no. 768, p. 202, Bibcode:2000PASP..112..202M, doi:10.1086/316512
Junor, W.; Biretta, J. A. (1994), "The Inner Light-Month of the M87 Jet", ใน Zensus, J. Anton; Kellermann; Kenneth I. (บ.ก.), Compact Extragalactic Radio Sources, Proceedings of the NRAO workshop held at Socorro, New Mexico, February 11–12, 1994, Green Bank, WV: National Radio Astronomy Observatory (NRAO), p. 97, Bibcode:1994cers.conf...97J