Authors
Hüseyin Irmak
Department of Mathematics, Faculty of Science, Çankırı Karatekin University, Çankırı, Turkey
© 2020 Hüseyin Irmak, Olga Engel, published by Sapientia Hungarian University of Transylvania
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.