Study protocol for a randomized trial comparing two electroacupuncture waveforms for different severity groups of Bell palsy - Bian, Zhiyuan; Wang, Jiawei; Fang, Fei; Yu, Binyan; Shi, Yan; Wan, Yijia; Hong, Mei; Ji, Conghua; Shao, Xiaomei; Liang, Yi; Fang, Jianqiao; Sun, Jing (Frontiers in Neurology, 2024)