Visual analysis based on the research of SARS and COVID-19: a 20-year bibliometric study. - Qifang Liang; Buping Liu; Chunping Liu; Wenxing Liu; Xiaoxue Han; Limei Wan; Xiaobo Chen; Peng wu; Hongyu Li; Yujiao Sun; Yubin Yang; Weixiong Chen (BIC, 2021)