Columbia subject headings:
Harvard subject headings:
Coal mines and mining--Germany--Lower Lusatia--History--19th century.
Lignite--Germany--Lower Lusatia.
Princeton subject headings:
Coal mines and mining--Germany--Lower Lusatia--History--19th century.
Lignite industry--Germany--Lower Lusatia--History--19th century.
Lignite--Germany--Lower Lusatia.