Hồi, T. T. B. .; Kiên, P. T.; Hoa, V. T. .; Trang, N. T. T. .; Anh, N. T. . Some Epidemiological, Clinical and Subclinical Characteristics With Chronic Obstructive Pulmonary Disease (COPD) at Hai Phong Lung Hospital in 2021. TC YHDP 2023, 33, 14.