Li, Mingming
Jiang, Hao
Gu, Kuo
Sun, Xuechao
Gu, Jing
Li, Chunming
Wang, Guonian
Funding for this research was provided by:
Department of Education, Heilongjiang Province (12511282)
Health and Family Planning Commission of Heilongjiang Province (2006-448; 2011-148; 2018192)
Article History
Received: 26 September 2019
Accepted: 9 March 2020
First Online: 16 April 2020