Books by United States. Coal Commission
Bituminous coal losses and min
Bituminous coal losses and mining methods in Pennsylvania
[Report on investments and pro
[Report on investments and profits in anthracite mining
[Report on the anthracite indu
[Report on the anthracite industry.]
[Report on the bituminous coal
[Report on the bituminous coal industry
[Report on the bituminous mine
[Report on the bituminous mine workers and their homes]
Irregularity of employment in
Irregularity of employment in the coal industry