1. FAO. FAOSTAT, Food and Agriculture Organization of the United Nations, Rome, Italy 2015. http://www.fao.org/faostat/en/.
2. Thornton P, Jones P, Owiyo T, Kruska R, Herrero M, Kristjanson P. Mapping climate vulnerability and poverty in Africa. Report to the Department for International Development. 2006.
3. Livestock-a driving force for food security and sustainable development;R Sansoucy;World Animal Review,1995
4. Livestock production: recent trends, future prospects;PK Thornton;Philosophical Transactions of the Royal Society of London B: Biological Sciences,2010
5. Felius M. Genus Bos: Cattle breeds of the world. Genus Bos: cattle breeds of the world. 1985.