Text and Data Mining valid from 2019-02-14
Received: 14 October 2018
Accepted: 7 February 2019
First Online: 14 February 2019
Ethics approval and consent to participate
: This study was approved by the Research Ethics Board of the Institute for Development of Human Research Protection, Thailand on November 23, 2016.
: Not applicable.
: The authors declare that they have no competing interests.
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