Paturel, G.; Fouque, P.; Bottinelli, L.; Gouguenheim, L.; Fouque; Bottinelli; Gouguenheim. Studeni 1989. An extragalactic database. I - The Catalogue of Principal Galaxies. Astronomy and Astrophysics Supplement Series (ISSN 0365-0138). 80 (3): 299–315. Bibcode:1989A&AS...80..299PCS1 održavanje: više imena: authors list (link)
