Levesque, E. M.; Massey, P.; Olsen, K. A. G.; Plez, B.; Josselin, E.; Maeder, A.; Meynet, G. (2005). ”The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not as Cool as We Thought” (på engelska). The Astrophysical Journal 628 (2): sid. 973. doi:10.1086/430901.