The present status of four luminous variables in M 33 R. F. Viotti, C. Rossi, V. F. Polcaro, F. Montagni, R. Gualandi and L. Norci A&A, 458 1 (2006) 225-234 Published online: 16 October 2006 DOI: 10.1051/0004-6361:20065099