Costs of mining under bolted roof and timbered roof in bituminous coal mines /
by M.J. Ackerman and J.J. Wallace.
APA Citation
Ackerman, M. J., Wallace, J. J., United States. Bureau of Mines. (1961). Costs of mining under bolted roof and timbered roof in bituminous coal mines. Washington, D.C.: U.S. Dept. of the Interior, Bureau of Mines.
MLA Citation
Ackerman, M. J, Joseph J Wallace, and United States. Bureau of Mines. Costs of Mining Under Bolted Roof And Timbered Roof In Bituminous Coal Mines. Washington, D.C.: U.S. Dept. of the Interior, Bureau of Mines, 1961.
Warning: These citations may not always be complete (especially for serials).