Copyright Notice

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgment of the work's authorship and initial publication in this journal.

Please note that the journal has changed its copyright policy. From vol.40, 2018 onwards, the author will retain the copyright if the article is accepted for publication.