Pismis 18

Number of stars per data source

	Reference  444 :    6 stars
	Reference  469 :    1 star

444: Moffat A.F.J., Vogt N.; (1973) Astron. Astrophys. Suppl. 10, 135; Southern open stars clusters. III. UBV-Hbeta photometry of 28 clusters between galactic longitude 297 and 353; 1973A&AS...10..135M
469: Klare G., Neckel T.; (1977) Astron. Astrophys. Suppl. 27, 215; UBV Hbeta and polarization measurements of 1660 southern OB stars; 1977A&AS...27..215K