This journal provides immediate access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge. With permitted reuse, articles are freely available to subscribers and the wider public. All articles published in open access will be immediately and permanently free for everyone to read and download. We continuously work with our author communities to select the best license options: Creative Commons Attribution Share Alike (CC BY SA).

You are free to:

1. Share — copy and redistribute the material in any medium or format for any purpose, even commercially.
2. Adapt — remix, transform, and build upon the material for any purpose, even commercially.
3. The licensor cannot revoke these freedoms as long as you follow the license terms.

Under the following terms:

1. Attribution — You must give appropriate credit , provide a link to the license, and indicate if changes were made . You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
2. ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
3. No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.

Notices:

You do not have to comply with the license for elements of the material in the public domain or where your use is permitted by an applicable exception or limitation .

No warranties are given. The license may not give you all of the permissions necessary for your intended use. For example, other rights such as publicity, privacy, or moral rights may limit how you use the material.