The UNESCO Libyan Valleys Survey, 21. Geomorphological studies of the Romano-Libyan farm, its floodwater control structures and weathered building stone at site Lm 4, at the confluence of Wadi el-Amud and Wadi Umm el-Bagul in the Libyan pre-desert. - Gilbertson, D.D (Libyan Studies, 21.1990, 1990)