Faculty of Applied Mathematics, AGH University of Kraków, al. Mickiewicza 30, 30-059, Kraków, Poland
https://ror.org/03613d656Department of Mathematics, Faculty of Electrical Engineering and Communication, Brno University of Technology, Technická 2848/8, 616 00, Brno, Czech Republic
https://ror.org/03s251g81Department of Mathematics, University of Craiova, Street A.I. Cuza 13, 200585, Craiova, Romania
Simion Stoilow Institute of Mathematics of the Romanian Academy, 010702, Bucharest, Romania
https://ror.org/01vevwk45Department of Mathematics, Zhejiang Normal University, 321004, Jinhua, Zhejiang, China