Selection in sympatric populations of Cepaea L.I. Mazon, M.A. Martinez de Pancorbo, A. Vicario, A.I. Aguirre, A. Estomba and C.M. Lostao Genet. Sel. Evol., 21 3 (1989) 269-281 DOI: 10.1051/gse:19890304