Monitoring luminous yellow massive stars in M 33: new yellow hypergiant candidates M. Kourniotis, A. Z. Bonanos, W. Yuan, L. M. Macri, D. Garcia-Alvarez and C.-H. Lee A&A, 601 (2017) A76 Published online: 08 May 2017 DOI: 10.1051/0004-6361/201629146