1. Information and Likelihood Theory: A Basis for Model Selection and Inference. Model Selection and Multimodel Inference: A Practical Approach;Burnham,2002
2. Rural Statistical Yearbook;China National Bureau of Statistics,2007
3. China 2006 National Agricultural Census Data Synthesis Summary;China National Bureau of Statistics,2008
4. China's Grain Production Economy: A Review by Regions;Crook,1993
5. Gridded Livestock of the World 2007;FAO,2007