J. L. Tonry; A. Dressler; J. P. Blakeslee; E. A. Ajhar; A. B. Fletcher; G. A. Luppino; M. R. Metzger; C. B. Moore (2001). ”The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distance”. Astrophysical Journal 546 (2): sid. 681–693. doi:10.1086/318301. Bibcode: 2001ApJ...546..681T.
Fumagalli, M.; Krumholz, M.R.; Prochaska, J.X; Gavazzi, G.; Boselli, A. (2009). ”Molecular Hydrogen Deficiency in H I-poor Galaxies and its Implications for Star Formation”. The Astrophysical Journal 697 (2): sid. 1811–1821. doi:10.1088/0004-637X/697/2/1811. Bibcode: 2009ApJ...697.1811F.
harvard.edu
adsabs.harvard.edu
J. L. Tonry; A. Dressler; J. P. Blakeslee; E. A. Ajhar; A. B. Fletcher; G. A. Luppino; M. R. Metzger; C. B. Moore (2001). ”The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distance”. Astrophysical Journal 546 (2): sid. 681–693. doi:10.1086/318301. Bibcode: 2001ApJ...546..681T.
Vollmer, B.; Cayatte, V.; Boselli, A.; Balkowski, C.; Duschl, W.J. (1999). ”Kinematics of the anemic cluster galaxy NGC 4548. Is stripping still active?”. Astronomy and Astrophysics 349: sid. 411–423. Bibcode: 1999A&A...349..411V.
Fumagalli, M.; Krumholz, M.R.; Prochaska, J.X; Gavazzi, G.; Boselli, A. (2009). ”Molecular Hydrogen Deficiency in H I-poor Galaxies and its Implications for Star Formation”. The Astrophysical Journal 697 (2): sid. 1811–1821. doi:10.1088/0004-637X/697/2/1811. Bibcode: 2009ApJ...697.1811F.
seds.org
messier.seds.org
William C. Williams Letter, Sky and Telescope, December 1969, p. 376. Upptagen 13 april 2011
Students for the Exploration and Development of Space Messier 91, Upptagen online 14 april 2011