1. Department of Mathematics, COMSATS University Islamabad, Attock Campus, Attock, Pakistan
2. Université de Sousse, Institut Supérieur d’Informatique et des Techniques de Communication, H. Sousse 4000, Tunisia
3. China Medical University Hospital, China Medical University, Taichung 40402, Taiwan
4. Department of Mathematics and Applied Mathematics, Sefako Makgatho Health Sciences University, Ga-Rankuwa, South Africa
5. Department of Mathematics, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia