Published on in Vol 6, No 3 (2020): Jul-Sep
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/18880, first published
.
1 South China Normal University, Guangzhou, China
2 City University of Hong Kong, Hong Kong, China (Hong Kong)
3 Sun Yat-sen University, Guangzhou, China