"Testing safety catches on mine cages, Lake Superior district."; "Cash, Frank E. (Frank Errette)", "Pearce, Clyde M."; "Iron mines and mining--Safety appliances--Lake States--Equipment and supplies."; "Pearce, Clyde M.", "Cash, Frank E. (Frank Errette)"; "1945"; "

Serial issue. Issued as: United States. Bureau of Mines. Information circular, 7325 (1945:June).

"; ""; "P19476"; "pec"; "Iron mines and mining--Safety appliances--Lake States--Equipment and supplies."; "14256"; .