1. School of Mathematics and Statistics Beijing Institute of Technology Beijing, P.R. China
2. Department of Mathematics and Statistics Hazara University, Mansehra, KPK, Pakistan
3. Department of Mathematics Abdul Wali Khan University, Mardan, KPK, Pakistan
4. Beijing key Laboratory on MCAACI, Beijing Institute of Technology, Beijing, P.R. China
5. Department of Mathematics Abbottabad University of Science and Technology, Abbottabad, KPK, Pakistan