Funding for this research was provided by:
The study was partly funded by COST action IS1405.
Text and Data Mining valid from 2019-08-09
Received: 12 June 2018
Accepted: 17 June 2019
First Online: 9 August 2019
Ethics approval and consent to participate
: This is a systematic review of already published primary sources and as such no further ethical approval was required.
: Not applicable.
: The authors declare that they have no competing interests.