Authors
Ireneusz Stefaniuk
Faculty of Mathematics and Natural Sciences, University of Rzeszow, Rzeszow, Poland
Bogumił Cieniek
Faculty of Mathematics and Natural Sciences, University of Rzeszow, Rzeszow, Poland
Iwona Rogalska
Faculty of Mathematics and Natural Sciences, University of Rzeszow, Rzeszow, Poland
Ihor S. Virt
The Ivan Franko State Pedagogical University in Drohobycz, Drohobycz, Ukraine
Faculty of Mathematics and Natural Sciences, University of Rzeszow, Rzeszow, Poland
Agnieszka Kościak
Faculty of Mathematics and Natural Sciences, University of Rzeszow, Rzeszow, Poland