1. Department of Mathematics, University of Engineering and Technology, Lahore 54840, Pakistan
2. Dipartimento di Scienza e Alta Tecnologia, Universita dell’Insubria, Via Valleggio 11, 22100 Como, Italy
3. Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Comte d’Urgell 187, 08036 Barcelona, Spain
4. Department of Mathematics, King Abdulaziz University, Jeddah 21589, Saudi Arabia