The journal applies the license CC BY (a Creative Commons Attribution 4.0 International license). This license allows authors to keep ownership of the copyright of their papers. But this license permits any user to download, print out, extract, reuse, archive, and distribute the article, so long as appropriate credit is given to the authors and the source of the work. The license ensures that the article will be available as widely as possible and that the article can be included in any scientific archive.