1. * Department of Mathematics, Faculty of Science, Mansoura University , , Mansoura , EGYPT
2. ** Department of Mathematics, Faculty of Education – Al-Nadirah, Ibb University , Ibb , YEMEN
3. *** Near East University, Operational Research Center in Healthcare, Near East Boulevard , PC: , Nicosia/Mersin 10 , TURKEY , Section of Mathematics, International Telematic University Uninettuno , Corso Vittorio Emanuele II 39 , , Roma , ITALY