1. ADF (Africa Development Fund) 2002. The federal Democratic Republic of Ethiopia: Agricultural sector review. Agricultural and Rural Development Department, Addis Ababa.
2. Atsbi World Vision 2004. Atsbi World Vision climatic data (2000–2004), Atsbi
3. Bationo A., Lompo F. and Koala S. 1998. Research on nutrient flows and balances in West Africa: state-of-the-art. Agric. Ecosyst. Environm. 71: 19–35
4. Bebe B.O. 2003. Herd dynamics of smallholder dairy in the Kenya highlands. Ph.D. Thesis. Wageningen University, Wageningen, The Netherlands .
5. Belay T. 1992. Erosion: Its effect on properties and productivities of Eutric Nitosols in Gununo area, southern Ethiopia and some techniques of its control. African Studies Series A9. University of Bern, Bern, Switzerland.