Funding for this research was provided by:
This research received funding from the Fundamental Research Funds for the Central Universities
Article History
First Online: 12 October 2019
Compliance with Ethical Standards
:
: The authors declare that they have no conflict of interest.
: The researcher obtained the ethical approval from the Human Research Ethics Committee (HREC) of the University of Hong Kong in June 2015 before starting the survey (Ref No.: EA3506011). All procedures of the survey were strictly in accordance with the ethical standards of the HREC guidelines.
: Informed consent was obtained from all participants and their parents.