Unveiling the oldest and most massive galaxies at very high redshift G. Rodighiero, A. Cimatti, A. Franceschini, M. Brusa, J. Fritz and M. Bolzonella A&A, 470 1 (2007) 21-37 Published online: 24 April 2007 DOI: 10.1051/0004-6361:20066497