6Ito, T. , Matsui, T. and Hong, W.P. Extended Design Method for Multi -row Stabilizing Piles against Landslide. Soils and Foundation,22, 1-13, (1982).
7Hassiotis, S., Chamean, J. 1., and Gunaratne. Design Method for Stabilization of Slopes with Piles. , J. of Geotech. Engrg. , ASCE,123 (4), 314-323, (1997) .