| Author: | Sayers, R. R. |
|---|---|
| Year: | 1931 |
| Document Type: | MAIN |
| Issuing Agency: | U.S. Dept. of Commerce, Bureau of Mines, |
| SUDOC: | C 22.11:6439 |
| Series: | Information circular / Bureau of Mines ; |
| Report Number: | 6439 |
| Subjects: | Mine ventilation--United States |
| Mine gases--United States | |
| Link: | https://hdl.handle.net/2027/mdp.39015095085851 |