The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars, V. V. Nesterov, A. V. Kuzmin, N. T. Ashimbaeva, A. A. Volchkov, S. Röser, and U. Bastian, Astronomy and Astrophysics Supplement Series110 (1995), pp. 367–370, Bibcode: 1995A&AS..110..367N.
