1. J. R. Brown, 1994 .State and transition models for rangelands. 2. Ecology as a basis for rangeland management: performance criteria for testing models., Tropical Grasslands,28:206 -213 .
2. Condition and Management of Range Land Based on Quantitative Ecology
3. P. G. Filet, 1994 .State and transition models for rangelands. 3. The impact of the state and transition model on grazing lands research, management and extension: a review., Tropical Grasslands,28:214 -222 .
4. B. D. Foran, G. Bastin, and K. A. Shaw .1986 .Range assessment and monitoring in arid lands: the use of classification and ordination in range survey., Journal of Environmental Management,22:67 -84 .
5. Range Condition Assessment and the Concept of Thresholds: A Viewpoint