4Davis JL, Annan A P. Ground penetrating radar for high resolution mapping of soil and rock stratigraphy. Geophysical Prospecting, 1989,37: 531-551.
5Daniels D J et al. , Introduction to subsurface radar.IEE Proceedings, 1988,135(4):278-320.
6Deng S K, Zuo Z R, Wang H L. , The application of ground penetrating radar to detection of shallow faults and eaves. GPR'94 Proceedings, 1994, Kitchener, Ontario, Canada, Vol. 3 of 3: 1115-1120.
7Deng S K, et al. , Ground penetrating radar imaging of railroad subgrade and subsoil strata. Proceedings of the 2nd International conference on Environmental and Engineering Geophysics, Wuhan, China, 2006, Vol. 1 of 2:550-554.
