Efficacy and safety of Lianhua Qingwen capsules combined with standard of care in the treatment of adult patients with mild to moderate COVID-19 (FLOSAN): protocol for a randomized, double-blind, international multicenter clinical trial - Zhan, Yang-Qing; Chen, Rui-Feng; Zheng, Qing-Shan; Li, Xing-Wang; Liu, You-Ning; Mootsikapun, Piroon; Chayakulkeeree, Methee; Arttawejkul, Pureepat; Lan, Truong Thi Ngoc; Liu, Gordon G.; Lu, Hong-Zhou; Liu, Qing-Quan; et al. (Journal of Thoracic Disease, 2023)