1. Faculté des Sciences de Tunis, LR10ES09 Modélisation Matématique, Analyse Harmonique et Théorie du Potentiel, Université de Tunis El Manar, Tunis 2092, Tunisie
2. College of Sciences, Imam Abdulrahman Bin Faisal University, 31441 Dammam, Kingdom of Saudi Arabia
3. Faculty of Education and Faculty of Mathematics and Physics, University of Ljubljana & Institute of Mathematics, Physics and Mechanics, 1000 Ljubljana, Slovenia