8FAO. The State of Food and Agriculture 2008 [ EB/OL]. http ://www. fao. org.
9Avery D. Biofuels, Food or Wildlife? The Massive Land Cost of U. S. Ethanol [ J ]. Issue Analysis ,2006, (5) : 14 - 18.
10Dong X B, Ulgiati S, Yan M C, et al. Energy and eMergy Evaluation of Bioethanol Production from Wheat in Henan Province,China [ J ]. Energy Policy ,2008,36 ( 10 ) :3882 - 3892.