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.
McClure, R. D. (May 1, 1983), "The binary nature of the barium stars. II - Velocities, binary frequency, and preliminary orbits", Astrophysical Journal, Part 1, 268: 264–273, Bibcode:1983ApJ...268..264M, doi:10.1086/160951.
Brown, Jeffery A.; et al. (October 1989), "A search for lithium-rich giant stars", Astrophysical Journal Supplement Series, 71: 293–322, Bibcode:1989ApJS...71..293B, doi:10.1086/191375.
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.
McClure, R. D. (May 1, 1983), "The binary nature of the barium stars. II - Velocities, binary frequency, and preliminary orbits", Astrophysical Journal, Part 1, 268: 264–273, Bibcode:1983ApJ...268..264M, doi:10.1086/160951.
Brown, Jeffery A.; et al. (October 1989), "A search for lithium-rich giant stars", Astrophysical Journal Supplement Series, 71: 293–322, Bibcode:1989ApJS...71..293B, doi:10.1086/191375.