1. Allen, J. C., & Barnes, D. F. (1985). The causes of deforestation in developing countries.Annals of the Association of American Geographers 75, 163–84.
2. Allen, T. F. H. & Starr, T. B. (1982)Hierarchy: perspectives for ecological complexity. Chicago, IL: University of Chicago Press.
3. Allen, T. F. H., & Hoekstra, T. W. (1992).Toward a unified ecology, New York, NY: Columbia University Press.
4. U.S. Geological Survey Professional;J. R. Anderson,1976
5. ARC/INFO Version 7.0.4. (1996). Environmental Systems Research Institute, Inc., Redlands, CA.