1. Barakat, H. 1995: Contribution archéobotanique à l'histoire de la végétation dans le Sahara oriental et dans le Soudan central, Unpublished Ph.D. thesis , Université Aix-Marseille III.
2. ——— 1996: Anthracological studies in the Northeastern Sahara: methodology and preliminary results from Nabta Playa. In Krzyzaniak, L., Kroeper, K. and Kobusiewicz, M., editors, Interregional contacts in later prehistory of Northeastern Africa. Poznan Archaeological Museum, 61—69.