Authors
Kazimierz Nikodem
University of Bielsko-Biala, Department of Mathematics, Bielsko-Biała, Poland
Teresa Rajba
University of Bielsko-Biala, Department of Mathematics, Bielsko-Biała, Poland
© 2020 Kazimierz Nikodem, Teresa Rajba, published by University of Silesia in Katowice, Institute of Mathematics
This work is licensed under the Creative Commons Attribution 4.0 License.