GYES, A Multifibre Spectrograph for the CFHT P. Bonifacio, S. Mignot, J.-L. Dournaux, P. François, E. Caffau, F. Royer, C. Babusiaux, F. Arenou, C. Balkowski, O. Bienaymé et al. (32 more) EAS Publications Series, 45 (2010) 219-222 Published online: 15 February 2011 DOI: 10.1051/eas/1045037