Columbia subject headings:
Limes (Roman boundary)--Congresses.
Rome--Boundaries--Congresses.
Rome--History, Military--Congresses.
Harvard subject headings:
Limes (Roman boundary)--Congresses.
Roman provinces--Congresses.
Rome--Boundaries--Congresses.
Rome--Colonies--Congresses.
Rome--History, Military--Congresses.
Princeton subject headings:
Limes (Roman boundary)--Congresses.
Rome--Boundaries--Congresses.
Rome--Frontier troubles--Congresses.
Rome--History, Military--Congresses.