1. Faculté des Sciences, Laboratoire de Physique Théorique URAC 13, Université Mohammed V – Agdal. Av. Ibn Battouta, B.P. 1014, Rabat, Morocco
2. The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, Miramare-Trieste, Italy
3. Mathematics Department, College of Science, University of Bahrain, P.O. Box, 32038, Bahrain
4. Mathematics Department, Faculty of Science, Aswan University, Aswan, Egypt