2[4]Bleecker ER.Similarities and differences in asthma and COPD.The Dutch hypothesis.Chest,2004,126:(2 Suppl):93S-95S.
3[5]Silva GE,Sherrill DL,Guerra S,et al.Asthma as a risk factor for COPD in a longitudinal study.Chest,2004,126:59-65.
4[7]Alladi M,Raya P,Lebaka NR,et al.Clinical presentation and predictors of outcome in patients with severe acute exacerbation of chronic obstructive pulmonary disease requiring admission to intensive care unit.BMC Pulm Med,2006,6:27-35.