Dupont, Lydie M.; Leroy, Suzanne A. G. (1996): Steps toward drier climatic conditions in northwestern Africa during the upper Pliocene. Yale University Press, New Haven, CT, United States, In: Vrba, Elisabeth S. (editor), Denton, George H. (editor), Partridge, Timothy C. (editor), Burckle, Lloyd H. (editor), Paleoclimate and evolution, with emphasis on human origins, 289-298, georefid:1997-047307