Affiliation: | 1. +20?235876998+20?23573486;2. Department of Engineering Mathematics, Faculty of Engineering, Cairo University, , Orman, Giza, 12221 Egypt;3. Department of Mathematics, Faculty of Science, Mansoura University, , Mansoura, 35516 Egypt;4. Department of Mathematics, Faculty of Science, Hail University, , Hail, 2440 KSA |