^Haggkvist, L.; Oja, T. (1970), "Results of BV photometry 1969-70 (Uppsala refractor)", Private Communication (Private Communication), Bibcode:1970Priv.........0H Private Communication.
^Lyubimkov, L. S.; et al. (October 2019), "Oxygen abundance and the N/C versus N/O relation for AFG supergiants and bright giants", Monthly Notices of the Royal Astronomical Society, 489 (2): 1533–1542, arXiv:1907.04634, Bibcode:2019MNRAS.489.1533L, doi:10.1093/mnras/stz2285