The contribution of oxygen-neon white dwarfs to the MACHO content of the Galactic halo J. Camacho, S. Torres, J. Isern, L. G. Althaus and E. García-Berro A&A, 471 1 (2007) 151-158 Published online: 26 June 2007 DOI: 10.1051/0004-6361:20077714