"Mine ventilation."; "Harrington, D. (Daniel), 1878-"; "Mine ventilation.", "Mine dusts.", "Air--Purification."; "Harrington, D. (Daniel), 1878-"; "1939"; "

Serial issue. Issued as: United States. Bureau of Mines. Information circular, 7047 (1939:Jan.).

"; ""; "P19469"; "pec"; "Mine ventilation.", "Air--Purification.", "Mine dusts."; "14256"; .