Hooghiemstra, Henry (1996): Environmental and paleoclimatic evolution in the late Pliocene-Quaternary Colombia. 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, 249-261, georefid:1997-047305