Text and Data Mining valid from 2019-04-23
Received: 6 November 2018
Accepted: 5 April 2019
First Online: 23 April 2019
Ethics approval and consent to participate
: Not applicable. This study does not require approval from an ethics committee, as it is a secondary analysis of publicly available, peer-reviewed publications.
: Not applicable.
: The authors declare that they have no competing interests.
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