1. Karadenz Technical University, Department of Mathematics, Faculty of Science, 61080, Trabzon, Trkye
2. National University of Uzbekistan Named After Mirzo Ulugbek, V.I. Romanovsky Institute of Mathemetics, Uzbekistan Academy of Sciences, Tashkent, Uzbekistan
3. National University of Uzbekistan Named After Mirzo Ulugbek, Tashkent, Uzbekistan