Smoking duration, respiratory symptoms, and COPD in adults aged =45 years with a smoking history.
Liu Y, Pleasants RA, Croft JB, Wheaton AG, Heidari K, Malarcher AM, Ohar JA, Kraft M, Mannino DM, Strange C. Smoking duration, respiratory symptoms, and COPD in adults aged =45 years with a smoking history. Int J Chron Obstruct Pulmon Dis. 2015; 10:1409-16.