Lithium abundances and extra mixing processes in evolved stars of M 67 B. L. Canto Martins, A. Lèbre, A. Palacios, P. de Laverny, O. Richard, C. H. F. Melo, J. D. do Nascimento Jr and J. R. De Medeiros A&A, 527 (2011) A94 Published online: 01 February 2011 DOI: 10.1051/0004-6361/201015015