Looking for obscured QSOs in the X-ray emitting ERO populationP. Severgnini, R. Della Ceca, V. Braito, P. Saracco, M. Longhetti, R. Bender, N. Drory, G. Feulner, U. Hopp, F. Mannucci and C. MarastonA&A, 431 1 (2005) 87-95DOI: https://doi.org/10.1051/0004-6361:20041587
