Hooghiemstra, Henry; Agwu, Chiori OC (1988): Changes in the vegetation and trade winds in equatorial Northwest Africa 140,000-70,000 yr BP, as deduced from two marine pollen records. Palaeogeography, Palaeoclimatology, Palaeoecology, 66(3-4), 173-213, doi:10.1016/0031-0182(88)90199-X