1. Y. M. Fu, W. M. Chen and S. L. Huang, In: International Symposium on Smart Structures and Microsystems, Hong Kong: PRC, 2000, 55-59.
2. Y. Ding, W. Ping and N. He: Chinese Journal of Geotechnical Engineering, Vol. 33(5) (2011), p.719–724(in Chinese).
3. J. Yang, Z. Q. Zhang and Q. Y. Zhang: Chinese Journal of Underground space and Engineering, Vol. 6(6) (2010), p.1246–1250(in Chinese).
4. S. Y. Lv, J. C. Guan and X. C. Liu: Geotechnical Investigation & Surveying, Vol. 38(s1) (2010), p.733–738.
5. Y. L. Zhang, C. X. Chen and X. W. Liu: Chinese Journal of Rock Mechanics and Engineering, Vol. 19(s) (2000), p.1061–1064. (in Chinese).