1. Mathematics Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
2. Mathematics Department, Science Faculty, Sohag University, Egypt
3. Mathematics Department, Science Faculty, Taif University, Saudi Arabia
4. Civil Engineering Department, Faculty of Technology, University of SidiBel Abbes, Algeria
5. Mathematics Department, Faculty of Mathematics and Computer Science, Transilvania University of Brasov, Romania