1. COMSATs University Islamabad, Lahore Campus, Lahore, Pakistan
2. Afro-Asian Institute, Lahore, Pakistan
3. Department of Mathematics, University of Sargdha, Sargodha 40100, Pakistan
4. Department of Mathematics, Faculty of Technical Science, University “Ismail Qemali”, 9400 Vlorë, Albania
5. Department of Mathematics, Islamic Azad University, Hamedan Branch, Hamedan, Iran