1. Spectral types in the open cluster IC 4665.
2. Allen, C. W. 1976, Astrophysical Quantities (3rd ed.; London: Athlone)
3. Alter, G., Balazs, B. & Ruprecht, J. 1970, Catalogue of Star Clusters and Associations (2nd ed.; Budapest: Akademiai Kiado)
4. The Cousins and Kron VRI systems