http://pec.lib.wvu.edu/record/P165641963Environmental dust study of anthracite coal mines of Eastern Pennsylvania. Journal article reprint from: <em>Journal of Occupational Medicine</em>, v.5:no.8 (1963:Aug.). Baier, Edward J.Diakun, R.Coal miners--Diseases--Pennsylvania.Coal mines and mining--Pennsylvania.Coal dust--Measurement--Pennsylvania.Pneumoconiosis.14256