Exercise Capacity and Prognosis Evaluation Methods for Patients with Chronic Obstructive Pulmonary Disease in the Community 
LI Haiyan, YANG Ting, YAO Fanxiu, LIU Hong
Chinese General Practice . 2021, (10): 1294 -1297 .  DOI: 10.12114/j.issn.1007-9572.2021.00.031