Characterization of the K2-18 multi-planetary system with HARPS - A habitable zone super-Earth and discovery of a second, warm super-Earth on a non-coplanar orbit
R. Cloutier, N. Astudillo-Defru, R. Doyon, X. Bonfils, J.-M. Almenara, B. Benneke, F. Bouchy, X. Delfosse, D. Ehrenreich, T. Forveille, C. Lovis, M. Mayor, K. Menou, F. Murgas, F. Pepe, J. Rowe, N. C. Santos, S. Udry and A. Wünsche
