Columbia subject headings:
Fortification, Roman--Germany--Congresses.
Germany--Antiquities, Roman--Congresses.
Limes (Roman boundary)--Germany--Congresses.
Limes (Roman boundary)--Raetia--Congresses.
Raetia--Antiquities, Roman--Congresses.
Harvard subject headings:
Excavations (Archaeology)--Germany--Congresses.
Fortification, Roman--Germany--Congresses.
Germany--Antiquities, Roman--Congresses.
Limes (Roman boundary)--Germany--Congresses.
Rome--History, Military--Congresses.
Princeton subject headings: