Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373
Rossiter, R. A. (February 1953), "Seventh list of new Southern double stars found at the Lamont-Hussey Observatory of the University of Michigan at Bloemfontein, South Africa.", Astronomical Journal, 58: 29–30, Bibcode:1953AJ.....58...29R, doi:10.1086/106804.
Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373
Rossiter, R. A. (February 1953), "Seventh list of new Southern double stars found at the Lamont-Hussey Observatory of the University of Michigan at Bloemfontein, South Africa.", Astronomical Journal, 58: 29–30, Bibcode:1953AJ.....58...29R, doi:10.1086/106804.