Columbia subject headings:
Harvard subject headings:
Aachen (Germany)--Antiquities.
Excavations (Archaeology)--Germany--Aachen.
Flint--Germany--Aachen--History--To 1500.
Lousberg (Aachen, Germany)
Quarries and quarrying--Germany--Aachen--History--To 1500.
Stone age--Germany--Aachen.
Princeton subject headings:
Aachen (Germany)--Antiquities.
Excavations (Archaeology)--Germany--Aachen.
Flint--Germany--Aachen--History--To 1500.
Lousberg (Aachen, Germany)
Quarries and quarrying--Germany--Aachen--History--To 1500.
Stone age--Germany--Aachen.