[Epidemilogical investigation of pneumoconiosis characteristics in Ningxia from 2002 to 2006].
Wang
Qi
Q
Ma
Fu-Hai
FH
Wang
Guan-Mei
GM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D011009:Pneumoconiosis / Q000453:epidemiology*