(en) N. Houk et A. P. Cowley, University of Michigan Catalogue of two-dimensional spectral types for the HD stars, vol. 1, (Bibcode1975mcts.book.....H)
(en) Ralph Elmer Wilson, General Catalogue of Stellar Radial Velocities, Washington, Carnegie Institution of Washington, (Bibcode1953GCRV..C......0W)