Funding for this research was provided by:
Naresuan University (R2560C031)
Received: 5 October 2017
Accepted: 19 January 2018
First Online: 27 January 2018
Ethics approval and consent to participate
: This study was approved by the Ethics Board of Naresuan University (project number 402/59). Written informed consent for an interview was obtained from each subject.
: Not applicable.
: The authors declare that they have no competing interests.
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