Messier 70

1. ^ Goldsbury, Ryan m. fl.. (December 2010), «The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters», The Astronomical Journal 140 (6): 1830–1837, arXiv:1008.2755, Bibcode 2010AJ....140.1830G, DOI:10.1088/0004-6256/140/6/1830. 
2. ^ ^{a b c} «SIMBAD Astronomical Object Database». Results for NGC 6681. Besøkt 17. november 2006. 
3. ^ ^{a b} Boyles, J. m. fl.. (november 2011), «Young Radio Pulsars in Galactic Globular Clusters», The Astrophysical Journal 742 (1): 51, arXiv:1108.4402, Bibcode 2011ApJ...742...51B, DOI:10.1088/0004-637X/742/1/51. 
4. ^ Shapley, Harlow; Sawyer, Helen B. (august 1927), «A Classification of Globular Clusters», Harvard College Observatory Bulletin (849): 11–14, Bibcode 1927BHarO.849...11S. 
5. ^ distance × sin( diameter_angle / 2 ) = 34 ly. radius
6. ^ ^{a b} Forbes, Duncan A.; Bridges, Terry (mai 2010), «Accreted versus in situ Milky Way globular clusters», Monthly Notices of the Royal Astronomical Society 404 (3): 1203–1214, arXiv:1001.4289, Bibcode 2010MNRAS.404.1203F, DOI:10.1111/j.1365-2966.2010.16373.x. 
7. ^ «Tight and Bright». ESA/Hubble Picture of the Week. Besøkt 13. april 2012. 

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