http://pec.lib.wvu.edu/record/P194631938Methods for protection against silicosis and when they are justified.<p> Serial issue. Issued as: United States. Bureau of Mines. <em>Information circular</em>, 6989 (1938:Feb.). </p>Harrington, D. (Daniel), 1878-Silicosis.Industrial hygiene. Lungs--Dust diseases.Occupational diseases.14256