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Vitral, Eduardo; Kremer, Kyle; Libralato, Mattia; Mamon, Gary A.; Bellini, Andrea (2022), "Stellar graveyards: clustering of compact objects in globular clusters NGC 3201 and NGC 6397", Monthly Notices of the Royal Astronomical Society, 514 (1), s. 806, arXiv:2202.01599 $2, Bibcode:2022MNRAS.514..806V, doi:10.1093/mnras/stac1337