Ali Sadeghi
Department of Mathematics, Faculty of Mathematical Sciences and Computer,
Shahid Chamran University of Ahvaz,Ahvaz-IRAN,
Mansour Saraj
Department of Mathematics, Faculty of Mathematical Sciences and Computer,
Shahid Chamran University of Ahvaz, Ahvaz-IRAN,
Nezam Mahdavi Amiri
Faculty of Mathematical Sciences, Sharif University of Technology, Tehran, Iran,