"The Importance of geology to the future of the coal industry. "; "Reger, David B. (David Bright), 1882-1958."; "Coal mines and mining.", "Geology."; "Reger, David B. (David Bright), 1882-1958."; "1939"; "Mimeograph of typescript. \"Paper presented at Third Annual Coal Conference, September 28, 29 & 30, 1939.\"
"; ""; "P5279"; "pec"; "Geology.", "Coal mines and mining."; "14256"; .