Messier 19

1. ^ ^{a b c d} «SIMBAD Astronomical Object Database». Results for NGC 6273. Besøkt 16. november 2006. 
2. ^ ^{a b} Boyles, J.; m.fl. (november 2011). «Young Radio Pulsars in Galactic Globular Clusters». The Astrophysical Journal. 742 (1): 51. Bibcode:2011ApJ...742...51B. arXiv:1108.4402 . doi:10.1088/0004-637X/742/1/51. 
3. ^ Shapley, Harlow; Sawyer, Helen B. (august 1927). «A Classification of Globular Clusters». Harvard College Observatory Bulletin (849): 11–14. Bibcode:1927BHarO.849...11S. 
4. ^ ^{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. Bibcode:2010MNRAS.404.1203F. arXiv:1001.4289 . doi:10.1111/j.1365-2966.2010.16373.x. 
5. ^ ^{a b} Thompson, Robert Bruce; Thompson, Barbara Fritchman (2007). «Illustrated Guide to Astronomical Wonders». Diy Science. O'Reilly Media, Inc.: 331. 
6. ^ Burnham, Robert (1978). Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System. Dover Books on Astronomy. 2 (2nd utg.). Courier Dover Publications. s. 1263. ISBN 0486235688. 

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