Binggeli, B.; Sandage, A.; Tammann, G. A. (September 1985). «Studies of the Virgo Cluster. II - A catalog of 2096 galaxies in the Virgo Cluster area. V - Luminosity functions of Virgo Cluster galaxies» (στα αγγλικά). The Astronomical Journal90: 1681. doi:10.1086/113874. ISSN0004-6256. Bibcode: 1985AJ.....90.1681B.
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Binggeli, B.; Sandage, A.; Tammann, G. A. (September 1985). «Studies of the Virgo Cluster. II - A catalog of 2096 galaxies in the Virgo Cluster area. V - Luminosity functions of Virgo Cluster galaxies» (στα αγγλικά). The Astronomical Journal90: 1681. doi:10.1086/113874. ISSN0004-6256. Bibcode: 1985AJ.....90.1681B.
Binggeli, B.; Sandage, A.; Tammann, G. A. (September 1985). «Studies of the Virgo Cluster. II - A catalog of 2096 galaxies in the Virgo Cluster area. V - Luminosity functions of Virgo Cluster galaxies» (στα αγγλικά). The Astronomical Journal90: 1681. doi:10.1086/113874. ISSN0004-6256. Bibcode: 1985AJ.....90.1681B.