Authors
Lhoussain El Fadil
Faculty of Sciences Dhar El Mahraz, Sidi Mohamed ben Abdellah University, Atlas-Fez, MOROCCO
© 2023 Lhoussain El Fadil, István Gaál, published by Slovak Academy of Sciences, Mathematical Institute
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.