Columbia subject headings:
Harvard subject headings:
Deutscher Braunkohlen-Industrie-Verein--History.
Lignite industry--Germany--History--20th century.
Lignite industry--Germany--History--21st century.
Princeton subject headings:
Deutscher Braunkohlen-Industrie-Verein--History.
Lignite industry--Germany--History--20th century.
Lignite industry--Germany--History--21st century.