State laws relating to coal-mine timbering.
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| Main Authors: | , |
|---|---|
| Corporate Author: | |
| Format: | Government Document Book |
| Language: | English |
| Published: |
Washington :
U.S. Govt. Print. Off,
1928.
|
| Series: | Technical paper (United States. Bureau of Mines) ;
421. |
| Subjects: |