1. Erzincan Binali Yıldırım University, Graduate School of Natural and Applied Sciences, Department of Mathematics, Yalnızbağ Campus, 24100 Erzincan, Turkey.
2. Erzincan Binali Yıldırım University, Faculty of Arts and Sciences, Department of Mathematics, Yalnızbağ Campus, 24100 Erzincan, Turkey.