Spectroscopy of the brightest optical counterparts of X-ray sources in the direction of M 31 and M 33D. Hatzidimitriou, W. Pietsch, Z. Misanovic, P. Reig and F. HaberlA&A, 451 3 (2006) 835-843DOI: https://doi.org/10.1051/0004-6361:20054402
