Collinder 228

Number of stars per data source

	Reference   89 :    1 star
	Reference  275 :    7 stars
	Reference  579 :   50 stars
	Reference  999 :    2 stars

89: Humphreys R.M., Strecker D.W., Ney E.P.; (1972) Astrophys. J. 172, 75; Spectroscopic and photometric observations of M supergiants in Carina; 1972ApJ...172...75H
275: Walborn N.R.; (1972) Astron. J. 77, 312; Spectral classification of OB stars in both hemisphere and the absolute-magnitude calibration; 1972AJ.....77..312W
579: Levato H., Malaroda S.; (1981) Publ. Astr. Soc. Pacific 93, 714; Spectral morphology in the open cluster Collinder 228; 1981PASP...93..714L
999: Houk N., Cowley A.P., Smith-Moore M.; University of Michigan (Ann Arbor) Vol 1 (1975), Vol 2 (1978), Vol 3 (1982), Vol 4 (1988), Vol 5 (1999); The University of Michigan Catalogue of two-dimensional Spectral Types for the HD stars; 1975mctd.book.....H