1. The Philadelphia Pulmonary Neoplasm Research Project
William Weiss, M.D., Herbert Seidman, M.B.A., Katharine R. Boucot, M.D. 
CHEST 
Volume 73, Issue 1, Pages (January 1978)
DOI: /chest
Copyright © 1978 The American College of Chest Physicians Terms and Conditions

2. Figure 1
Prevalence of expectoration during 48 months prior to and at radiographic detection in 33 cases of lung cancer (solid circles) and matched controls (open circles)
CHEST  , 57-61DOI: ( /chest )
Copyright © 1978 The American College of Chest Physicians Terms and Conditions

3. Figure 2
Prevalence of chronic cough during 48 months prior to and at radiographic detection in 33 cases of lung cancer (solid circles) and matched controls (open circles)
CHEST  , 57-61DOI: ( /chest )
Copyright © 1978 The American College of Chest Physicians Terms and Conditions

4. Figure 3
Prevalence of dyspnea during 48 months prior to and at radiographic detection in 33 cases of lung cancer (solid circles) and matched controls (open circles)
CHEST  , 57-61DOI: ( /chest )
Copyright © 1978 The American College of Chest Physicians Terms and Conditions