Author: | Barkley, J. F. |
---|---|
Additional Authors: | Burdick, L. R. |
Year: | 1937 |
Document Type: | USBI |
Issuing Agency: | U.S. Dept. of the Interior, Bureau of Mines, |
SUDOC: | I 28.27:6933 |
Series: | Information circular / United States Department of the Interior, Bureau of Mines ; |
Report Number: | 6933 |
Subject: | Coal--Classification |
Link: | https://hdl.handle.net/2027/mdp.39015077569419 |