1. D.Z. Gu: Similar Materials and Similar Models (China University of Mining and Technology Press, China 1995).
2. J.Y. Dong, J.H. Yang and G.X. Yang: Journal of China Coal Society, (2012) No. 37, pp.44-49. (In Chinese).
3. G.X. Chen, Y.H. Du, P.K. Qin and L. Zhang: Journal of Computational Science & Engineering, (2013) No. 8, pp.300-304. (In Chinese).
4. Q.F. Deng, Y.X. Luan, Y.A. Wang: Coal Mine Safety, (1989) No. 11, pp.5-10. (In Chinese).
5. J. F, Li, L. Yuan, Z.Z. Fu, et al: Journal of Computational Science & Engineering, vol. 7 (2013), pp.274-277.