Columbia subject headings:
Harvard subject headings:
Grubenhagen (Principality)--History.
Mineral industries--Germany--Grubenhagen (Principality)--History.
Mining engineering--Germany--Grubenhagen (Principality)--History.
Princeton subject headings:
Grubenhagen (Principality)--History.
Mineral industries--Germany--Grubenhagen (Principality)--History.
Mining engineering--Germany--Grubenhagen (Principality)--History.