1. Department of Mathematics and Statistics, University of Swat, Khyber Pakhtunkhawa, Pakistan
2. Govt, Girls Degree College Khwazakhela Swat, Pakistan
3. School of Science, Xi’an Polytechnic University, Xi’an, China
4. School of Mathematics, Northwest University, Xi’an, China
5. Govt, Girls Degree College Madyan Swat, Pakistan