1. China University of Mining and Technology, State Key Laboratory for Geomechanics and Deep Underground Engineering, Xuzhou, P. R. China + China University of Mining and Technology, School of Mechanics and Civil Engineering, Xuzhou, PR. China
2. China University of Mining and Technology, State Key Laboratory for Geomechanics and Deep Underground Engineering, Xuzhou, P. R. China + China University of Mining and Technology, School of Mechanics and Civil Engineering, Xuzhou, P.R. China
3. Department of Mathematics, Faculty of Sciences, HITEC University, Taxila Cantt, Pakistan