1. School of Science, Zhejiang University of Science and Technology, Hangzhou, P.R. China
2. Department of Mathematics, Division of Science and Technology, University of Education, Lahore, Pakistan
3. College of Mathematics and Systems Science, Shandong University of Science and Technology, Qingdao, P.R. China
4. Material Science Innovation and Modelling (MaSIM) Research Focus Area, North-West University, Mmabatho, South Africa