This journal provides immediate open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge. This journal is an open-access journal which means that all content is freely available without charge to users or institutions. Users are allowed to read, download, copy, distribute, print, search, or link to full-text articles in this journal without asking prior permission from the publisher or author.

As an open-access journal, all contents are freely available without charge to users or their institutions. Users are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles in this journal without prior permission from the publisher or the author (CC Attribution-ShareAlike 4.0).