Author/Authors :
Sedghi, S Department of Mathematics - Qaemshahr Branch - Islamic Azad University, Qaemshahr , Shobkolaei, N Department of Mathematics - Babol Branch - Islamic Azad University, Babol , Shahraki, M Department of Mathematics - Qaemshahr Branch - Islamic Azad University, Qaemshahr , Dosˇenovic´, T Faculty of Technology - University of Novi Sad - Bulevar Cara Lazara 1 - Novi Sad, Serbia