C. M. Fletcher, P. C. Elmes, A. S. Fairbairn, C. H. Wood
Fletcher C M, Elmes P C, Fairbairn A S, Wood C H.
Significance of Respiratory Symptoms and the Diagnosis of Chronic Bronchitis in a Working Population
Br Med J 1959; 2 :257
doi:10.1136/bmj.2.5147.257