In: L. Krzyzaniak, M. Kobusiewicz & J. Alexander (eds.), Environmental change and human culture in the Nile basin and northern Africa until the second millennium B.C. Studies in African Archaeology 4 (Poznan: Poznan Archaeological Museum) pp.213–223. ↑ Discovery of the ancient Abu Ballas Trail Retrieved 2020/04/20. ↑ Rudolf Kuper, The Abu Ballas Trail: Pharaonic Advances into the Libyan Desert, in: Z.Hawass and L.Pinch Brock (ed.), Egypt and the Dawn of the Twenty-First Century.