Epidemiological Characteristics of Hand, Foot, and Mouth Disease Outbreaks in Qingdao, 2009-2018 - Jia, Jing; Kong, Fei; Xin, Xueling; Liang, Jiwei; Xin, Hualei; Dong, Liyan; Jiang, Fachun (Iranian Journal of Public Health, 2021)