The Visual Orbit, the Stellar Diameter and the Magnitude Difference of the Spectroscopic Binary β Herculis, X. P. Pan, M. Shao, M. M. Colavita, B. E. Hines, J. T. Armstrong, C. S. Denisson, M. Vivekanand, D. Mozurkewich, R. S. Simon, K. J. Johnston, Bulletin of the American Astronomical Society22 (September 1990), p. 1335, Bibcode: 1990BAAS...22R1335P.
HR 6148, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line September 18, 2008.
vizier.u-strasbg.fr
HR 6148, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line September 18, 2008.