Authors
Anna Gąsior
anna.gasior@poczta.umcs.lublin.pl
Institute of Mathematics, Maria Curie-Skłodowska University, Lublin, Poland
anna.gasior@poczta.umcs.lublin.pl
© 2022 Anna Gąsior, Andrzej Szczepański, published by Pedagogical University of Cracow
This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 License.