Authors
Adrian Petruşel
Department of Mathematics, Babeş-Bolyai University, Academy of Romanian Scientists, Cluj-Napoca
Ioan A. Rus
Department of Mathematics, Babeş -Bolyai University, Cluj-Napoca, Romania
© 2020 Adrian Petruşel, Ioan A. Rus, published by West University of Timisoara
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.