1. Sun X.F. Fang X.S. Guan L.T.(1998)."Material Mechanics( )."M. Higher Education Publishing House.
2. Wu X.M. Hu Y.L. Li L.G. Chen J. Liu G.H. and Wang Y.F. (2004). "Directed Drilling and trenchless pipe laying technology. "M. Publishing House of China University of Geosciences