1. , , . 1998. Agricultural productivity in the United States. Agriculture Information Bulletin No. 740. U.S. Department of Agriculture: WA.
2. . 1963. Table for Statistics (2nd edn). Barnes and Noble: New York, NY.
3. . 1979. Agrarian Reform and Productivity in Developing Countries. Johns Hopkins Press: MD.
4. . 1987. Defining and debating the problem. In Land Degradation and Society, (eds). Methuen: London.
5. Understanding 20 Years of Change in West-Central Nepal: Continuity and Change in Lives and Ideas