RT Journal Article SR Electronic T1 Prevalence and risk factors of airflow obstruction in an elderly Chinese population JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society DO 10.1183/09031936.00058708 A1 F.W.S. Ko A1 J. Woo A1 W. Tam A1 C.K.W. Lai A1 J. Ngai A1 T. Kwok A1 D.S.C. Hui YR 2008 UL http://erj.ersjournals.com/content/early/2008/08/06/09031936.00058708.abstract AB