Steven D. Peterson, « DOUBLE GALAXIES. I. OBSERVATIONAL DATA ON A WELL-DEFINED SAMPLE », The Astrophysical Journal Supplement Series, vol. 40, , p. 527-575, 550 (DOI10.1086/190597, Bibcode1979ApJS..40.527P, lire en ligne)
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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)
Steven D. Peterson, « DOUBLE GALAXIES. I. OBSERVATIONAL DATA ON A WELL-DEFINED SAMPLE », The Astrophysical Journal Supplement Series, vol. 40, , p. 527-575, 550 (DOI10.1086/190597, Bibcode1979ApJS..40.527P, lire en ligne)
articles.adsabs.harvard.edu
Steven D. Peterson, « DOUBLE GALAXIES. I. OBSERVATIONAL DATA ON A WELL-DEFINED SAMPLE », The Astrophysical Journal Supplement Series, vol. 40, , p. 527-575, 550 (DOI10.1086/190597, Bibcode1979ApJS..40.527P, lire en ligne)