Influence of Healthcare Workers on Influenza Vaccination among Elderly People in Beijing:Qualitative Study 
YAO Xi,YU Mengke,WU Jiang,LYU Min,XIE Zheng
Chinese General Practice . 2020, (17): 2203 -2206 .  DOI: 10.12114/j.issn.1007-9572.2019.00.665