Papers presented before the second Symposium on Underground Mining : NCA/BCR Coal Conference and Expo III, October 19-20-21, 1976, Kentucky Fair and Exposition Center, Louisville, Kentucky / sponsored by National Coal Association [and] Bituminous Coal Research, Inc.
Papers presented before the second Symposium on Underground Mining : NCA/BCR Coal Conference and Expo III, October 19-20-21, 1976, Kentucky Fair and Exposition Center, Louisville, Kentucky / sponsored by National Coal Association [and] Bituminous Coal Research, Inc.