http://pec.lib.wvu.edu/record/P161831972Development of patterns of coal workers' pneumoconiosis in Pennsylvania and its association with respiratory impairment.<p> Journal article reprint from: <em>Annals of the New York Academy of Sciences</em>, v. 200 (1972:Dec.29).</p>Crawford, George M. Baier, Edward J.Beatty, J. A.Dessauer, P.Chest radiography.Coal miners--Diseases--Pennsylvania.Chest--Diseases.Coal mines and mining--Pennsylvania.Pneumoconiosis.Lungs--Dust diseases.Respiratory organs--Obstructions.14256