6Kirkby M.J., Le Bissonais Y., Coulthard T. J., et al. The Development of Land Quality Indicators for Soil Degradation by Water Erosion[J]. Agriculture·Ecosystems and Environment, 2000, 81 : 125- 135.
7Rod D.B. Lefroy, Hans- Dieter Bechstedt, Mohammad Rais. Indicators for Sustainable Land Management Based on Farmer Surveys in Vietnam, Indonesia, and Thailand [J]. Agriculture·Ecosystems and Environment, 2000, 81:137-146.
8Mandal D.K. et al. Development of A Land Quality Index for Sorghum in Indian Semi - arid Tropics (SAT) [J]. Agricultural Systems, 2001,70: 335- 350.
9Bouma J. Land Quality Indicators of Sustainable Land Management Across Scales [J]. Agriculture·Ecosystems and Environment, 2002,88:129- 136.
10Syers Keith, Sheldrick William, Lingard John. Nutrient Balance Changes as An Indicator of Sustainable Agriculture[R]. 17th WCSS,Thailand, 2002,14 - 21.
