1. Department of Mathematics, Abdul Wali Khan University Mardan, Pakistan
2. Department of Mathematics, Near East University TRNC, Mersin 10, Turkey
3. Department of Mathematics and Information Technology, The Education University of Hong Kong, 10 Lo Ping Road, Tai Po, New Territories, Hong Kong
4. Department of Mathematics, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
5. School of Mathematical Sciences, Dublin City University, Ireland