NGC 6939

Number of stars per data source

	Reference   50 :  301 stars
	Reference   51 :  305 stars
	Reference  232 :  310 stars

50: Chincarini G.; (1963) Contr. Asiago no 138; The open cluster NGC 6939
51: Cannon R.D., Lloyd C.; (1969) Monthly Notices Roy. Astron. Soc. 144, 449; The main sequence gap and red giant clump of NGC 6939; 1969MNRAS.144..449C
232: Barkhatova K.A., Steinberg M.K.; (1963) Collected Works in Astronomy, Sverdlosk, 1, 14; NGC 6939