Columbia subject headings:
Harvard subject headings:
Fortification, Roman--France, Southwest--Congresses.
Fortification, Roman--Spain--Congresses.
France, Southwest--Antiquities, Roman--Congresses.
Spain--Antiquities, Roman--Congresses.
Princeton subject headings:
Fortification, Roman--France, Southwest--Congresses.
Fortification, Roman--Spain--Congresses.
France, Southwest--Antiquities, Roman--Congresses.
Spain--Antiquities, Roman--Congresses.