NILAKSHI, S.R.; PANDEY, A.K.; MOHAN, V. A study of spatial structure of galactic open star clusters. S. 153–162. Astronomy and Astrophysics [online]. Leden 2002 [cit. 2017-01-23]. Roč. 383, čís. 1, s. 153–162. Dostupné online. DOI10.1051/0004-6361:20011719. Bibcode2002A&A...383..153N. (anglicky)
TRUMPLER, R.J. Preliminary results on the distances, dimensions and space distribution of open star clusters. Lick Observatory bulletin. Berkeley: University of California Press, 1930, roč. 14, čís. 420, s. 154–188. Dostupné online [cit. 2017-01-24]. DOI10.5479/ADS/bib/1930LicOB.14.154T. Bibcode1930LicOB..14..154T. (anglicky)
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NILAKSHI, S.R.; PANDEY, A.K.; MOHAN, V. A study of spatial structure of galactic open star clusters. S. 153–162. Astronomy and Astrophysics [online]. Leden 2002 [cit. 2017-01-23]. Roč. 383, čís. 1, s. 153–162. Dostupné online. DOI10.1051/0004-6361:20011719. Bibcode2002A&A...383..153N. (anglicky)
TRUMPLER, R.J. Preliminary results on the distances, dimensions and space distribution of open star clusters. Lick Observatory bulletin. Berkeley: University of California Press, 1930, roč. 14, čís. 420, s. 154–188. Dostupné online [cit. 2017-01-24]. DOI10.5479/ADS/bib/1930LicOB.14.154T. Bibcode1930LicOB..14..154T. (anglicky)