| Author: | Lewis, Walter E. | 
|---|---|
| Year: | 1950 | 
| Document Type: | USBI | 
| Issuing Agency: | U.S. Dept. of the Interior, Bureau of Mines, | 
| SUDOC: | I 28.27:7571 | 
| Series: | Information circular / United States Department of the Interior, Bureau of Mines ; | 
| Report Number: | 7571 | 
| Subjects: | Hydraulic engineering | 
| Tunneling--Minnesota | |
| Link: | https://hdl.handle.net/2027/mdp.39015078455501 |