1. Department of Mathematics and Statistics, Riphah International University, I-14 Islamabad, Pakistan
2. Quantum Leap Africa (QLA), AIMS Rwanda Centre, Remera Sector KN 3, Kigali, Rwanda
3. Institut de Mathematiques et de Sciences Physiques (IMSP/UAC), Laboratoire de Topologie Fondamentale, Computationnelle et leurs Applications (Lab-ToFoCApp), BP 613, Porto-Novo, Benin
4. African Center for Advanced Studies, P.O. Box 4477, Yaounde, Cameroon
5. Department of Mathematics, University of the Punjab, Lahore 54590, Pakistan