Text and Data Mining valid from 2019-08-19
Received: 2 April 2019
Accepted: 23 July 2019
First Online: 19 August 2019
Ethics approval and consent to participate
: This kind of research did not need approval from the ethics committees in our faculties.
: All data were published under previous consent of participants. The subjects in the photos in this article consented to their image being taken and included in a publication
: The authors declare that they have no competing interests.