Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
Castelli, F. (November 1991), "Effective temperature and gravity c0 and beta indices for B-type stars", Astronomy and Astrophysics, 251: 106, Bibcode:1991A&A...251..106C.