4Donald H Gray Robbin B Sotir. Biotechnical and Soil Bioengineering Slopestabilization[M]. New York:John Wiley & Sons,Inc, 1996.
5Gray,D H. Influence of vegetation on the stability of slope ,proceedings ,International Conference on Vegetation and Slope[C]. Oxford Institution of Civil Engineers ,University Museum, 1994.1- 23.
6Gray, D H, A t Leiser. Biotechnical Slope Protection and Erosion Control[M]. New York : Van Nostrand Reinhold,1982.
7Greenway,D R. Vegetation and Slope Stability[A]. In :Slope stability[M], edited by M G Anderson,K S Riehards. NewYork :Wiley, 1987.
8USDA Soil Conservation Service. Chapter 18: Soil bioengineering for upland slope protection and erosion reduction[M]. Part 650,210- EFH ,Engineering Field Handbook, 1992.
9Tschantz,B A, J D Weaver. Tree growth on earth dams:A survey of state policy and practice[M]. Civil Engineering Department, University of Tennessee, 1998,36.
10Patric,J H,et al. Soil water absorption by mountain and piedmont[J]. Forests Soil Science of America Proceedings,1965,29:303-308.