Variations in the lithium abundances of turn off stars in the globular cluster 47 Tucanae P. Bonifacio, L. Pasquini, P. Molaro, E. Carretta, P. François, R. G. Gratton, G. James, L. Sbordone, F. Spite and M. Zoccali A&A, 470 1 (2007) 153-159 Published online: 10 May 2007 DOI: 10.1051/0004-6361:20077227