Delfosse et al.: The HARPS search for southern extra-solar planets XXXV. Super-Earths around the M-dwarf neighbors Gl433 and Gl667C. arxiv:1202.2467.
Bonfils, X.; Delfosse, X.; Udry, S.; Forveille, T.; Mayor, M.; Perrier, C.; Bouchy, F.; Gillon, M.; Lovis, C.; Pepe, F.; Queloz, D.; Santos, N. C.; Ségransan, D.; Bertaux, J.-L.: The HARPS search for southern extra-solar planets XXXI. The M-dwarf sample. arxiv:1111.5019.
Tuomi et al.: Bayesian search for low-mass planets around nearby M dwarfs. Estimates for occurrence rate based on global detectability statistics. arxiv:1403.0430.