7Halbert RJ, Isonaka S, George D, et al. Interpreting COPD prevalence estimates:what is the true burden of disease?. Chest, 2003,123 (5) : 1684-1692.
8Murray CJL,Lopez AD. Alternative projections of mortality and disability by cause 1990-2020 : Global Burden of Disease Study. Lancet, 1997, 349 (9064) : 1498-1504.
9Zhong NS, Wang C, Ran PX. Prevalence of chronic obstructive pulmonary disease in China. Am J Respir Crit Care Med,2007,176(8) :753-760.
