Smith, Robert T. (1941). "The Radial Velocity of a Peculiar Nebula". Publications of the Astronomical Society of the Pacific. ج. 53: 187. Bibcode:1941PASP...53..187S. DOI:10.1086/125301.
Burbidge, E. Margaret (1964). "The Strange Extragalactic Systems: Mayall's Object and IC 883". Astrophysical Journal. ج. 140: 1617. Bibcode:1964ApJ...140.1617B. DOI:10.1086/148070.
Smith, Robert T. (1941). "The Radial Velocity of a Peculiar Nebula". Publications of the Astronomical Society of the Pacific. ج. 53: 187. Bibcode:1941PASP...53..187S. DOI:10.1086/125301.
Burbidge, E. Margaret (1964). "The Strange Extragalactic Systems: Mayall's Object and IC 883". Astrophysical Journal. ج. 140: 1617. Bibcode:1964ApJ...140.1617B. DOI:10.1086/148070.