1. Feeding the Ten Billion;Evans,2001
2. FAO, 2006. Livestock's long shadow. Steinfeld, H., Gerber, P., Wassenaar, T., Castel, V., Rosales, M., de Haan, C., FAO, Rome, 407 pp.
3. The state of food and agriculture 2008, biofuels, prospects, risks and opportunities;FAO,2008