Effect of breathing exercises on oxidative stress biomarkers in humans: A systematic review and meta-analysis oleh Ting-ting Li, Hong-ying Wang, Hui Zhang, Ping-ping Zhang, Ming-chen Zhang, Hai-yang Feng, Xiao-yong Duan, Wen-bo Liu, Wen-bo Liu, Xiao-wen Wang, Xiao-wen Wang, Zhong-guang Sun