Author: | Schrenk, H. H. |
---|---|
Year: | 1939 |
Document Type: | USBI |
Issuing Agency: | U.S. Dept. of the Interior, Bureau of Mines, |
SUDOC: | I 28.27:7086 |
Series: | Information circular / United States. Bureau of Mines ; |
Report Number: | 7086 |
Subjects: | Respirators (Medical equipment) |
Breathing apparatus | |
Link: | https://hdl.handle.net/2027/mdp.39015078534842 |