Technological change and productivity in the bituminous coal industry 1920-60.
- Washington : USDL , 1961
- ii, 137p. ; 25 cm.
- Bulletin .
Includes bibliographical references and index.
Coal resources
Coal mining
Productivity
Technological change
333.82 / US
Includes bibliographical references and index.
Coal resources
Coal mining
Productivity
Technological change
333.82 / US