[Study on the epidemiological difference of four kinds of chronic respiratory disease in the urban and rural areas of China].
He
Quan-ying
QY
Department of Respiratory Medicine, the People's Hospital, Peking University, Beijing, China.
Ma
Yan-liang
YL
Zhang
Rong-bao
RB
Yang
Rui-hong
RH
Mu
Xin-lin
XL
D002681:China / Q000453:epidemiology; D002908:Chronic Disease; D006801:Humans; D012140:Respiratory Tract Diseases / Q000453:epidemiology*; D012424:Rural Population; D014505:Urban Population