4Nerlove M. Estimates of elasticities of supply of selected agricultural commodities[J].Journal of Farm Economics.1956(38): 496-509.
5Fox K A. A Spatial equilibrium model of the live stock-feed economy in the United States[J].Economitrica.1953(41):547-566.
6Pindyck R S. Julio J. Rotemberg. The extess comovement of commodity prices[J]. Economie Journal, 1990,100(403): 1173-1189.
7Lapp J S, Smith V H. Aggregate sources of relative price variability among agricultural commodities[J].American Journal of Agricultural EconomiCS. 1992.74(1) : 1-9.
8Trostle R. Global agricultural supply and demand: factors contributing to the recent increase in food commodity prices[R].USDA, 2008:143-175.
9Tokgoz S. The impact of energy markets on the EU agricultural sector, center for agricultural and rural development[D]. Iowa State University, 2009.
