Funding for this research was provided by:
Hong Kong Polytechnic University (ZVNX)
Text and Data Mining valid from 2020-02-13
Received: 17 September 2019
Accepted: 7 February 2020
First Online: 13 February 2020
Compliance with Ethical Standards
: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.