| Author: | Crawford, Frank Stevens, |
|---|---|
| Year: | 1931 |
| Document Type: | MAIN |
| Issuing Agency: | U.S. Dept. of Commerce, Bureau of Mines, |
| SUDOC: | C 22.11:6521 |
| Series: | Information circular / Bureau of Mines ; |
| Report Number: | 6521 |
| Subjects: | Iron mines and mining--Michigan |
| Iron mines and mining--Michigan--Safety measures | |
| Link: | https://hdl.handle.net/2027/mdp.39015095085448 |