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Nesterov, V. V.; Kuzmin, A. V.; Ashimbaeva, N. T.; Volchkov, A. A.; Röser, S.; Bastian, U. (1995). »The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars«. Astronomy and Astrophysics Supplement Series. 110: 367. Bibcode:1995A&AS..110..367N. CDS ID III/182.
Cannon, Annie. J. (1936). »The Henry Draper extension«. Annals of Harvard College Observatory. 100: 1. Bibcode:1936AnHar.100....1C.
Nesterov, V. V.; Kuzmin, A. V.; Ashimbaeva, N. T.; Volchkov, A. A.; Röser, S.; Bastian, U. (1995). »The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars«. Astronomy and Astrophysics Supplement Series. 110: 367. Bibcode:1995A&AS..110..367N. CDS ID III/182.
Nesterov, V. V.; Kuzmin, A. V.; Ashimbaeva, N. T.; Volchkov, A. A.; Röser, S.; Bastian, U. (1995). »The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars«. Astronomy and Astrophysics Supplement Series. 110: 367. Bibcode:1995A&AS..110..367N. CDS ID III/182.
Henry Draper Catalogue and Extension, A. J. Cannon and E. C. Pickering, CDS ID III/135A.
Nesterov, V. V.; Kuzmin, A. V.; Ashimbaeva, N. T.; Volchkov, A. A.; Röser, S.; Bastian, U. (1995). »The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars«. Astronomy and Astrophysics Supplement Series. 110: 367. Bibcode:1995A&AS..110..367N. CDS ID III/182.