Epidemiological survey on pulmonary functions of people over 40 years old in Laiyuan County, Hebei Province
Qiao Qingzhe, Zhang Xin, He Xianghong, Xi Suya
Clinical Focus . 2022, (7): 627 -630 .  DOI: 10.3969/j.issn.1004-583X.2022.07.008