1. Coppin, N. J., & Richards, I. G. (1990). Use of vegetation in civil engineering. London: Butterworth.
2. Endo, T., & Tsuruta, T. (1969). The effect of tree roots upon the shearing strength of soil. Annual Report of the Hokkaido Branch, Tokyo Forest Experimental Station, 18, 168–179.
3. Gray, D. H., & Leiser, A. T. (1989). Biotechnical slope protection and erosion control. New York: Van Nostrand Reinhold.
4. Gray, D. H., & Ohashi, H. (1983). Mechanics of fiber reinforcement in sand. Journal of Geotechnical Engineering, ASCE, 109(3), 335–353.
5. Gray, D. H., & Sotir, R. B. (1996). Biotechnical and soil bioengineering slope stabilization. New York: Wiley.