Ultraluminous X-ray sources out to z ~ 0.3 in the COSMOS field V. Mainieri, C. Vignali, A. Merloni, F. Civano, S. Puccetti, M. Brusa, R. Gilli, M. Bolzonella, A. Comastri, G. Zamorani et al. (52 more) A&A, 514 (2010) A85 Published online: 26 May 2010 DOI: 10.1051/0004-6361/200912544