Falls of roof in mines operating in the Pittsburgh Coal Bed, West Virginia / by J.W. Paul and J.N. Geyer.
Saved in:
| Main Author: | |
|---|---|
| Corporate Author: | |
| Other Authors: | |
| Format: | Government Document Book |
| Language: | English |
| Published: |
Washington :
U.S. Govt. Print. Off,
1933.
|
| Series: | Technical paper (United States. Bureau of Mines) ;
547. |
| Subjects: |