| Author: | Muir, Neal M. |
|---|---|
| Year: | 1947 |
| Document Type: | N/A |
| SUDOC: | I 28.23:4075 |
| Series: | United States Bureau of Mines Reports |
| Report Number: | R. I. 4075 |
| Subjects: | Boring. |
| Fluorspar -- Illinois -- Hardin County. | |
| Mines and mineral resources -- Illinois -- Hardin County. | |
| Link: | http://digital.library.unt.edu/ark:/67531/metadc38472/ |