Aja viide. Aja lugu.

NGC 668 is a spiral galaxy located 200 million light-years away^[2] in the constellation Andromeda. It was discovered by astronomer Édouard Stephan on December 4, 1880^[3] and is a member of Abell 262.^[4]^[5]^[6]^[7]

References

^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j "NASA/IPAC Extragalactic Database". Results for NGC 668. Retrieved 2018-11-13.
^ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2018-11-14.
^ "New General Catalog Objects: NGC 650 - 699". cseligman.com. Retrieved 2018-11-14.
^ P., Fouque; E., Gourgoulhon; P., Chamaraux; G., Paturel (May 1992). "Groups of galaxies within 80 Mpc. II - The catalogue of groups and group members". Astronomy and Astrophysics Supplement Series. 93: 211. Bibcode:1992A&AS...93..211F. ISSN 0365-0138.
^ M., Garcia, A. (July 1993). "General study of group membership. II - Determination of nearby groups". Astronomy and Astrophysics Supplement Series. 100: 47. Bibcode:1993A&AS..100...47G. ISSN 0365-0138.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Giuricin, Giuliano; Marinoni, Christian; Ceriani, Lorenzo; Pisani, Armando (November 2000). "Nearby Optical Galaxies: Selection of the Sample and Identification of Groups". The Astrophysical Journal. 543 (1): 178–194. arXiv:astro-ph/0001140. Bibcode:2000ApJ...543..178G. doi:10.1086/317070. ISSN 0004-637X. S2CID 9618325.
^ "Detailed Object Classifications". ned.ipac.caltech.edu. Retrieved 2018-11-16.