The role of long-acting muscarinic antagonist/long-acting β agonist fixed-dose combination treatment for chronic obstructive pulmonary disease in China: a narrative review - Zhou, Ji’an; Zhang, Jing; Zhou, Min; Hang, Jingqing; Zhang, Min; Han, Fengfeng; Zhu, Huili (Journal of Thoracic Disease; Vol 13, No 11 (November 30, 2021): Journal of Thoracic Disease, 2021)