| Institution: | 1. Département des Sciences Fondamentales, de Droit et des Humanités, IMIP University of Maroua, P.O. Box 46, Maroua, Cameroon;2. Department of Physics and Astronomy, Dickinson College, Carlisle, Pennsylvania 17013, USA;3. Laboratory of Mechanics, Department of Physics, University of Yaoundé I, Cameroon;4. Department of Physics, Faculty of Science, University of Maroua, P.O. Box 46, Maroua, Cameroon;5. The Abdus Salam International Centre for Theoretical Physics, P.O. Box 538, Strada costiera 11, I-34014 Trieste, Italy |
