The copyrights of open-access articles in the German Multidisciplinary Publishing Center (GMPC) journals are retained by the author(s). All articles are licensed under the Creative Commons Attribution 4.0 International License (CC BY-NC), implying that all published papers by GMPC can be read and downloaded for free.

Authors have to inform the editorial office at submission if any specific conditions, such as one linked to funding, do not permit this license. In this case, exceptions will be granted according to the Publisher's discretion.

GMPC will not publish material from other publications without permission; therefore, authors must acquire permission from copyright holders before reproducing any published material (figures, schemes, tables, or any excerpt from a text) for which they do not have a copyright.

The permission is acquired under the following conditions:

• i) The published work that authors do not hold its copyright.
• ii) Significant extracts from others.
• iii) Unchanged or slightly modified figures, tables, graphs, charts, schemes, and artworks.
• iv) Photos, which you do not retain copyright.

The permission is not required in the following cases:

• i) Designing own table from published data; in this case, authors are asked to mention that: "Data from..." or "Adapted from...".
• ii) Adequate short quotes
• iii) Significant completely redrawn or significantly modified figures.

Patents: It is the author's responsibility to resolve all patent applications and IP issues before publication. Applications and registrations for patents must comply with GMPC-policy on Conflict of Interest Policy.