Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
Houk, N. (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 2. Dept. of Astronomy, University of Michigan. Bibcode:1978mcts.book.....H.