X-Shooter GTO: chemical analysis of a sample of EMP candidates E. Caffau, P. Bonifacio, P. François, M. Spite, F. Spite, S. Zaggia, H.-G. Ludwig, L. Monaco, L. Sbordone, R. Cayrel et al. (4 more) A&A, 534 (2011) A4 Published online: 20 September 2011 DOI: 10.1051/0004-6361/201117530