van der Wal, S. E.; van Genderen, A. M. (April 1988). "VBLUW-photometry of the two FO Ib supergiants HD 80404 and HD 90853 and the K5 Ib supergiant HD 85891 with its associated cluster". Astronomy and Astrophysics. 195: 172–178. Bibcode:1988A&A...195..172V.