1. Hardorp, J., Theile, I. & Voigt, H. H. 1965, Luminous Stars in the Northern Milky Way V (Hamburg-Bergedorf: Hamburger Sternwarte and Warner and Swasey Obs.)
2. Photoelectric photometry - an approach to data reduction
3. Houk, N. & Smith-Moore, M. 1988, Michigan Catalogue of Two-Dimensional Spectral Types for the HD Stars, Vol. 4 (Ann Arbor: Univ. Michigan, Dept. Astron.)
4. Astronomical Measurements in the Infrared
5. UBVRI photometric standard stars around the celestial equator