"Shortwall coal mining in the United States."; "Peng, Syd S., 1939-"; "Coal mines and mining--Safety measures.", "Coal mines and mining--Research.", "Mine roof bolting."; "Peng, Syd S., 1939-"; "1976"; "

Serial issue. Issued as: West Virginia University. Coal Research Bureau. Technical report, no. 119. \"Prepared for publication in Coal Age, 81, 3, (March, 1976), 82-88.\"

"; ""; "P12412"; "pec"; "Mine roof bolting.", "Coal mines and mining--Safety measures.", "Coal mines and mining--Research."; "14256"; .