NGC 663

Number of stars per data source

	Reference   84 :    2 stars
	Reference   87 :    3 stars
	Reference   88 :   10 stars

84: Pietrzynski G.; (1996) Acta Astron. 46, 357; Variable stars in the young open cluster NGC 663; 1996AcA....46..357P
87: Pietrzynski G.; (1997) Acta Astron. 47, 211; A CCD search for variable stars in young open cluster NGC 663; 1997AcA....47..211P
88: Pigulski A., Kopacki G., Kolaczkowski Z.; (2001) Acta Astron. 51, 159; A CCD search for variable stars of spectral B in the northern hemisphere open clusters. IV. NGC 663; 2001AcA....51..159P