The Extended Chandra Deep Field-South survey: Optical spectroscopy of faint X-ray sources with the VLT^* and Keck

J. D. Silverman, V. Mainieri, M. Salvato, G. Hasinger, J. Bergeron, P. Capak, G. Szokoly, A. Finoguenov, R. Gilli, P. Rosati, P. Tozzi, C. Vignali, D. M. Alexander, W. N. Brandt, B. D. Lehmer, B. Luo, D. Rafferty, Y. Q. Xue, I. Balestra, F. E. BauerM. Brusa, A. Comastri, J. Kartaltepe, A. M. Koekemoer, T. Miyaji, D. P. Schneider, E. Treister, L. Wisotski, M. Schramm