Columbia subject headings:
Geology--Germany--Harz Mountains Region--Guidebooks.
Mines and mineral resources--Germany--Harz Mountains Region--Guidebooks.
Harvard subject headings:
Geology--Germany--Harz Mountains Region--Guidebooks.
Mines and mineral resources--Germany--Harz Mountains Region--Guidebooks.
Princeton subject headings:
Geology--Germany--Harz Mountains Region--Guidebooks.
Harz Mountains Regions (Germany)--Guidebooks.
Mines and mineral resources--Germany--Harz Mountains Region--Guidebooks.