The work of the United States Bureau of Mines

Year:	1930
Document Type:	MAIN
Issuing Agency:	U.S. Dept. of Commerce, Bureau of Mines,
SUDOC:	C 22.11:6257
Series:	Information circular / Bureau of Mines ;
Report Number:	6257
Subjects:	Mines and mineral resources--United States
	Mineral industries--United States
Link:	https://hdl.handle.net/2027/mdp.39015095083575