Optical and infrared properties of active galactic nuclei in the Lockman Hole E. Rovilos, S. Fotopoulou, M. Salvato, V. Burwitz, E. Egami, G. Hasinger and G. Szokoly A&A, 529 (2011) A135 Published online: 19 April 2011 DOI: 10.1051/0004-6361/201015763