Age and mass of solar twins constrained by lithium abundance J. D. do Nascimento Jr, M. Castro, J. Meléndez, M. Bazot, S. Théado, G. F. Porto de Mello and J. R. De Medeiros A&A, 501 2 (2009) 687-694 Published online: 13 May 2009 DOI: 10.1051/0004-6361/200911935