Author: | Conway, J. A. |
---|---|
Year: | 1931 |
Document Type: | MAIN |
Issuing Agency: | U.S. Dept. of Commerce, Bureau of Mines, |
SUDOC: | C 22.11:6405 |
Series: | Information circular / United States Department of the Interior, Bureau of Mines ; |
Report Number: | 6405 |
Subjects: | Mines and mineral resources--Pennsylvania |
Quarries and quarrying--Pennsylvania | |
Link: | https://hdl.handle.net/2027/mdp.39015095085687 |