Larrasoana, J. C.; Roberts, A. P.; Rohling, E. J.; Winkhofer, M.; Wehausen, R. (2003): Three million years of monsoon variability over the northern Sahara. Springer-Verlag, Heidelberg, Federal Republic of Germany, Climate Dynamics, 21 (7-8), 689-698, georefid:2004-026625