9Shiba M. Measuring the efficiency of managerial and technical perlbmiancs in forestry activities by means of DEA [ J]. Inter J of Forest Engineering, 1997, 8 (1) : 7 -19.
10LeBel L G and Stuart W B. Technical efficiency evaluation of logging contractors using a nonparametric model [ J ]. Inter J of Forest Engineering, 1998, 9 (2): 15-24.
10Allan Rae and Heng-yun Ma. "Projecting China's Grains and Meats Trade: Sensitivity to Agricultural Productivity Growth", Presented at International Agricultural Trade Research Consortium Annua General Meeting Session, on Research Plan and Reports December San An-tonio, Texas [R]. 2003, 14 - 16.