A.M. Garcia, General study of group membership. II - Determination of nearby groups, in Astronomy and Astrophysics Supplement Series, 100 #1, luglio 1993, pp.47-90, Bibcode:1993A&AS..100...47G.
Nathan Smith, Jon C. Mauerhan, S. Bradley Cenko, Mansi M. Kasliwal, Jeffrey M. Silverman, Alexei V. Filippenko, Avishay Gal-Yam, Kelsey I. Clubb, Melissa L. Graham, Douglas C. Leonard, J. Chuck Horst, G. Grant Williams, Jennifer E. Andrews, Shrinivas R. Kulkarni, Peter Nugent, Mark Sullivan, Kate Maguire, Dong Xu e Sagi Ben-Ami, PTF11iqb: Cool supergiant mass-loss that bridges the gap between Type IIn and normal supernovae, in Monthly Notices of the Royal Astronomical Society, vol.449, n.2, 2015, pp.1876-1896, DOI:10.1093/mnras/stv354.
Nathan Smith, Jon C. Mauerhan, S. Bradley Cenko, Mansi M. Kasliwal, Jeffrey M. Silverman, Alexei V. Filippenko, Avishay Gal-Yam, Kelsey I. Clubb, Melissa L. Graham, Douglas C. Leonard, J. Chuck Horst, G. Grant Williams, Jennifer E. Andrews, Shrinivas R. Kulkarni, Peter Nugent, Mark Sullivan, Kate Maguire, Dong Xu e Sagi Ben-Ami, PTF11iqb: Cool supergiant mass-loss that bridges the gap between Type IIn and normal supernovae, in Monthly Notices of the Royal Astronomical Society, vol.449, n.2, 2015, pp.1876-1896, DOI:10.1093/mnras/stv354.