K. Watanabe, H. Sei, T. Nishiyama, and Y. Ishii. “Static Axial Reciprocal Load Test of Cast-in-place Nodular Concrete Pile and Nodular Diaphrgm Wall”. Geotechnical Engineering Journal of the SEAGS & AGSSEA, vol. 42, no. 2, June 2011, pp. 11-19, doi:10.14456/seagj.2011.18.