Year: | 1967 |
---|---|
Document Type: | USBI |
Issuing Agency: | U.S. Bureau of Mines, |
SUDOC: | I 28.27:8357 |
Series: | Information circular / United States. Bureau of Mines ; |
Report Number: | 8357 |
Subjects: | Coal mines and mining--Safety measures |
Coal mines and mining--United States | |
Link: | https://hdl.handle.net/2027/mdp.39015078464412 |