(2005) Prevalence of chronic obstructive pulmonary disease in Korea:a population-based spirometry survey,

Korea national statistical office statistical mata DB,

(2005) Global initiative for chronic obstructive lung disease Global strategy for diagnosis and prevention of COPD,

(1977) Surgical treatment for pulmonary emphysema,

(2003) A randomized trial comparing lung-volumereduction surgery with medical therapy for severe emphysema,

(2006) Bronchoscopic lung volume reduction for end-stage emphysema:report on the first 98 patients,

(2004) VENT:international studyof bronchoscopic lung volume reduction as a palliative treatment for emphysema,

(2006) Biologic lung volume reduction for advanced emphysema,

(2003) Bronchial fenestration improves expiratory flow in emphysematous human lungs,