Liu, Wenqiang
Liu, Jun
Wei, Bifan
Duan, Haimeng
Hu, Wei
Funding for this research was provided by:
National Natural Science Foundation of China (61370019, 61672419)
National Natural Science Foundation of China (61672418, 61532004)
National Natural Science Foundation of China (61532015)
National Key Research and Development Program of China (2016YFB1000903)
MOE Research Center for Online Education Funds (No.2016YB165)
Ministry of Education Innovation Research Team (IRT17R86)
Article History
Received: 10 October 2017
Revised: 5 January 2018
Accepted: 18 April 2018
First Online: 3 May 2018