(en) G. de Vaucouleurs, A. de Vaucouleurs et J.R. Corwin, Second reference catalogue of bright galaxies, The University of Texas monographs in astronomy, , 170p. (Bibcode1937AnLun...6....1H)
(en) G. de Vaucouleurs, A. de Vaucouleurs et J.R. Corwin, Second reference catalogue of bright galaxies, The University of Texas monographs in astronomy, , 396p. (ISBN0292755074 et 9780292755079, Bibcode1976RC2...C......0D)
R. A. White, M. Bliton, S. Bhavsar, J. O. Bornmann, M. Ledlow et C. Loken, «A Catalog of Nearby Poor Clusters of Galaxies», Bulletin of the American Astronomical Society, vol.31, , p.979 (Bibcode1999AAS...194.8804W, lire en ligne[PDF])
A.M. Garcia, «General study of group membership. II -Determination of nearby groups», Astronomy and Astrophysics Supplement Series, vol.100 #1, , p.47-90 (Bibcode1993A&AS..100...47G, lire en ligne)|format=PDF
A.M. Garcia, «General study of group membership. II -Determination of nearby groups», Astronomy and Astrophysics Supplement Series, vol.100 #1, , p.47-90 (Bibcode1993A&AS..100...47G, lire en ligne)|format=PDF
R. A. White, M. Bliton, S. Bhavsar, J. O. Bornmann, M. Ledlow et C. Loken, «A Catalog of Nearby Poor Clusters of Galaxies», Bulletin of the American Astronomical Society, vol.31, , p.979 (Bibcode1999AAS...194.8804W, lire en ligne[PDF])
Abraham Mahtessian, «Groups of galaxies. III. Some empirical characteristics», Astrophysics, vol.41, no3, , p.308-321 (DOI10.1007/BF03036100, lire en ligne, consulté le )
Abraham Mahtessian, «Groups of galaxies. III. Some empirical characteristics», Astrophysics, vol.41, no3, , p.308-321 (DOI10.1007/BF03036100, lire en ligne, consulté le )