NGC 1901

Number of stars per data source

	Reference  220 :    3 stars
	Reference  999 :    3 stars

220: Gray R.O., Garrison R.F.; (1989) Astrophys. J. Suppl. 70, 623; The late A-type stars: refined MK classification, confrontation with Stromgren photometry, and the effects of rotation; 1989ApJS...70..623G
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