Dou, Qianqian http://orcid.org/0000-0002-9782-9741
Wong, Ka Wai http://orcid.org/0000-0001-8529-2126
Li, Yang http://orcid.org/0000-0003-0357-4520
Ng, Ka Ming http://orcid.org/0000-0001-5439-4744
Article History
Received: 4 April 2018
Accepted: 19 June 2018
First Online: 22 June 2018
Compliance with ethical standards
:
: The authors declare that there is no conflict of interest regarding the publication of this paper.