Yan, Weirong, Liwei Cheng, Li Tan, Miao Yu, Shaofa Nie, Biao Xu, Lars Palm, and Vinod Diwan. 2013. “Using Medications Sales from Retail Pharmacies for Syndromic Surveillance in Rural China”. Online Journal of Public Health Informatics 5 (1). https://doi.org/10.5210/ojphi.v5i1.4490.