title: [Work hard to explore the risking factors for chronic obstructive pulmonary disease with epidemiological methods].
authors.forename: Yong-jian
authors.initials: YJ
authors.lastname: Xu
mesh_terms: D006801:Humans; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000209:etiology*; D012307:Risk Factors