1. Department of Mathematics, COMSATS University Islamabad, Lahore Campus, Pakistan
2. Department of Mathematics, University of Education Lahore, Vehari Campus, Pakistan
3. Department of Mathematics, COMSATS University Islamabad, Vehari Campus, Pakistan
4. Dambi Dollo University, Oromia, Ethiopia
5. Department of Mathematics, Federal University Gashua, Yobe State, Nigeria