Survey on prevalence of chronic obstructive pulmonary disease in rural areas of Tangshan
YU Chang-li;ZHAO Chun-mei;LI Xiao-xu;GAO Chang-jun;YUN Ling;YAO Zuo-yi;XU Ying-jun;WANG Hong-yang
CLINICAL FOCUS . 2009, (21): 1857 -1860 .