1. Alvord ED: Development of native agriculture and land tenure in southern Rhodesia, Unpublished ms. Harare: Rhodes House, University of Zimbabwe; 1958.
2. Aylen D: Who built the first contour ridges. The Rhodesia Agricultural J 1941, 36: 452-484.
3. Bratton M: Drought, food and the social organisation of small farmers in Zimbabwe. In Drought and hunger in Africa denying famine a future. Edited by: Glantz M. New York: Cambridge University Press; 1987:31-35.
4. Camberlin P, Moron V, Okoola R, Philippon N, Gitau W: Components of rainy seasons’ variability in Equatorial East Africa: onset, cessation, rainfall frequency and intensity. Theor Appl Climatol 2009. 10.1007/s00704-009-0113-1
5. Conway G: The doubly green revolution. USA: Food for all in the twenty-first century. Penguin Books; 1997:334.