| Author: | Kelley, Laurence E. | 
|---|---|
| Year: | 1932 | 
| Document Type: | USBI | 
| Issuing Agency: | U.S. Dept. of Commerce, Bureau of Mines, | 
| SUDOC: | C 22.11:6602 | 
| Series: | Information circular / Bureau of Mines ; | 
| Report Number: | 6602 | 
| Subjects: | Shaft sinking--Costs | 
| Mining engineering | |
| Shaft sinking--Technique | |
| Link: | https://hdl.handle.net/2027/mdp.39015086485342 |