Collinder 121

Number of stars per data source

	Reference   10 :    4 stars
	Reference   11 :    7 stars
	Reference   20 :    1 star

10: Pel J.W.; (1975) Astron. Astrophys. Suppl. 24, 413; Five-channel photometry of cepheids and supergiants in the southern Milky Way; 1975A&AS...24..413P
11: Walraven Th., Walraven J.H.; (1977) Astron. Astrophys. Suppl. 30, 245; Five channel photometric observations of stars in the Magellanic Clouds and in the Milky Way; 1977A&AS...30..245W
20: Lub J., Pel J.W.; (1977) Astron. Astrophys. 54, 137; Properties of the Walraven VBLUW photometric system; 1977A&A....54..137L