Institution: | 1.Maths. Dept., Faculty of Science,Taif University,Taif,Saudi Arabia;2.Maths. Dept., Faculty of Science,Sohag University,Sohag,Egypt;3.Maths. Dept., Faculty of Education,King Abdul Aziz University,Jeddah,Saudi Arabia;4.Maths. Dept., Faculty of Science,SVU,Qena,Egypt |