4Joanne E. Norris. Root Reinforcement by Hawthorn and Oak Roots on a Highway Cut-Slope in Southern England[J] 2005,Plant and Soil(1-2):43~53
5S. Yokota,T. Fukuda,A. Iwamatsu,S. Uda,T. Wada,H. Masaki. The effect of rainwater infiltration within a slope of pyroclastic deposits, recorded using automated electric prospecting[J] 1998,Bulletin of Engineering Geology and the Environment(1):51~58