Zhang, Jie
Ma, Chenchao
Yang, Aimin
Zhang, Rongqiang
Gong, Jiannan
Mo, Fengfeng
Article History
Received: 13 May 2018
Accepted: 11 November 2018
First Online: 22 December 2018
Ethics approval and consent to participate
: This study is an analysis of secondary data from the NSCH, collected in 2011–2012.
: Not applicable.
: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
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