SOPHIE velocimetry of Kepler transit candidates - VI. An additional companion in the KOI-13 systemA. Santerne, C. Moutou, S. C. C. Barros, C. Damiani, R. F. Díaz, J.-M. Almenara, A. S. Bonomo, F. Bouchy, M. Deleuil and G. HébrardA&A, 544 (2012) L12DOI: https://doi.org/10.1051/0004-6361/201219899