Technology, employment, and output per man in copper mining /

Bibliographic Details
Main Author:	Leong, Yau Sing, 1899- (Author)
Format:	Government Document eBook
Language:	English
Published:	Philadelphia, Pennsylvania : Work Projects Administration, National Research Project : Department of the Interior, Bureau of Mines, 1940.
Series:	Mineral technology and output per man studies ; rept. no. E-12.
Subjects:	Copper mines and mining > United States. Miners > United States. Mining machinery. Copper mines and mining. Miners. United States.
Online Access:	https://purl.fdlp.gov/GPO/gpo88845