Hours and earnings in bituminous coal mining 1922, 1924, and 1926.
| Typ dokumentu: | Kniha |
|---|---|
| Jazyk: |
angličtina |
| Vydavatel: |
Washington :
Government printing office,
1927.
|
| Edice: |
Bulletin of the United States, Bureau of Labor Statistic ;
no. 454 |
|
|