Columbia subject headings:
Harvard subject headings:
Conservation of natural resources--European Union countries--Congresses.
Industrial archaeology--European Union countries--Congresses.
Mineral industries--Environmental aspects--European Union countries--Congresses.
Mines and mineral resources--European Union countries--History--Congresses.
Princeton subject headings:
Conservation of natural resources--European Union countries--Congresses.
Industrial archaeology--European Union countries--Congresses.
Mineral industries--Environmental aspects--European Union countries--Congresses.
Mines and mineral resources--European Union countries--History--Congresses.