Arafa A. Nasef
(1),
Mostafa K. El-Bably
(2),
Salama H. Shalil
(3),
Mostafa A. El-Gayar
(4)
(1)
Department of Physics and Engineering Mathematics, Faculty of Engineering, Kafrelsheikh University, Kafrelsheikh 33516, Egypt,
(2)
Department of Mathematics, Faculty of Science, Tanta University, Tanta 31527, Egypt,
(3)
Mathematics Department, Faculty of Science, Capital University (formerly Helwan University), Helwan 11795, Egypt
