Johnson, H. L. та ін. (1966), UBVRIJKL photometry of the bright stars, Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, т. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.