About this article
Published Online: Apr 30, 2020
Page range: 3 - 12
DOI: https://doi.org/10.2478/awutm-2018-0012
Keywords
© 2018 Adrian Petruşel et al., published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.
Petruşel, Adrian
Department of Mathematics, Babeş-Bolyai University, Academy of Romanian ScientistsCluj-Napoca
Rus, Ioan A.
Department of Mathematics, Babeş -Bolyai UniversityCluj-Napoca, Romania