Columbia subject headings:
Harvard subject headings:
Anthracite coal industry--Pennsylvania--History--20th century.
Coal miners--Labor unions--Pennsylvania--History--20th century.
Coal miners--Pennsylvania--History--20th century.
Foreign workers, Italian--Pennsylvania--History--20th century.
Princeton subject headings:
Anthracite coal industry--Pennsylvania--History--20th century.
Coal miners--Labor unions--Pennsylvania--History--20th century.
Coal miners--Pennsylvania--History--20th century.
Foreign workers, Italian--Pennsylvania--History--20th century.