Method and cost of mining the Pittsburgh, or no. 8, coal bed in a 100 percent mechanized mine in eastern Ohio / by W.F. Hazen and E.J. Christy.
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| Format: | Government Document Book |
| Language: | English |
| Published: |
Washington, D.C. :
U.S. Dept. of Commerce, Bureau of Mines,
1929.
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| Series: | Information circular (United States. Bureau of Mines) ;
6200. |
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