Comparative study of nectar secretion and attractivity to bees of two lines of spring-type faba bean ( Vicia faba L var equina Steudel) J. Pierre, J. Le Guen, M.H. Pham Delègue, J. Mesquida, R. Marilleau and G. Morin Apidologie, 27 2 (1996) 65-75 DOI: 10.1051/apido:19960201