1. Department of Mathematics, College of Science, University of Hail, Hail 2440, Saudi Arabia
2. Department of Mathematics, Faculty of Science, Mansoura University, Mansoura 35516, Egypt
3. Section of Mathematics, International Telematic University Uninettuno, Corso Vittorio Emanuele II, 39, 00186 Roma, Italy
4. Department of Mathematics and Computer Science, University of Oradea, Univeritatii nr. 1, 410087 Oradea, Romania
5. Department of Automated Electrical Systems, Ural Power Engineering Institute, Ural Federal University, 620002 Yekaterinburg, Russia