Open Access
Review
Issue
4open
Volume 3, 2020
Article Number 2
Number of page(s) 19
Section Mathematics - Applied Mathematics
DOI https://doi.org/10.1051/fopen/2020001
Published online 27 April 2020

© P.E. Ricci, Published by EDP Sciences, 2020

Licence Creative CommonsThis is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.