About this article
Published Online: Oct 03, 2018
Page range: 97 - 104
Received: Nov 09, 2017
Accepted: Apr 02, 2018
DOI: https://doi.org/10.21042/AMNS.2018.1.00007
Keywords
© 2018 M. Isabel García-Planas and Tetiana Klymchuk, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.
Isabel García-Planas, M.
Departament de Matemàtiques, Universitat Politécnica de CatalunyaBarcelona, Spain
Klymchuk, Tetiana
Departament de Matemàtiques, Universitat Politécnica de CatalunyaBarcelona, Spain