Year: | 1948 |
---|---|
Document Type: | USBI |
Issuing Agency: | U.S. Dept. of the Interior, Bureau of Mines, |
SUDOC: | I 28.27:7449 |
Series: | Information circular / Bureau of Mines ; |
Report Number: | 7449 |
Subjects: | Coal mines and mining--Safety measures |
Anthracite coal | |
Link: | https://hdl.handle.net/2027/mdp.39015077578550 |