Author: | Ryan, W. D. |
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Year: | 1931 |
Document Type: | USBI |
Issuing Agency: | U.S. Dept. of Commerce, Bureau of Mines, |
SUDOC: | C 22.11:6428 |
Series: | Information circular / Bureau of Mines ; |
Report Number: | 6428 |
Subject: | Mine safety |
Link: | https://hdl.handle.net/2027/mdp.39015077576604 |