Engaruka
Westerberg, L.-O., Holmgren, K., Börjeson, L., Håkansson, N.T., Laulumaa, V., Ryner, M., and Öberg, H., 2010: The development of the ancient irrigation system at Engaruka, Northern Tanzania: Physical and societal factors. The Geographical Journal, doi: 10.1111/j.1475-4959.2010.00370.x