1. Department of Mathematics, Islamia College, Peshawar, Pakistan
2. Department of Mathematics, COMSATS University Islamabad, Attock, Pakistan
3. Department of Natural Sciences and Humanities, University of Engineering and Technology, Lahore (RCET), Lahore, Pakistan
4. UFR of Mathematics and Computer Science, University Felix Houphouet Boigny of Cocody, Abidjan, Côte d’Ivoire