1. Department of Mathematical Sciences, Indian Institute of Technology (BHU), Varanasi, India
2. Institute of Mathematical Sciences, University of Malaya, Kuala Lumpur, Malaysia
3. Faculty of Business & Information Science, UCSI University, Kuala Lumpur, Malaysia
4. Department of Mathematics, University of Mazandaran, Babolsar, Iran
5. Department of Mathematical Sciences, University of South Africa, Pretoria, South Africa
6. Department of Mathematics, King Saud University, Riyadh, Saudi Arabia