Columbia subject headings:
France--Relations--Germany--Congresses.
Germany--Relations--France--Congresses.
Harvard subject headings:
France--Boundaries--Germany--Congresses.
France--Historical geography--Congresses.
Germany--Boundaries--France--Congresses.
Germany--Historical geography--Congresses.
Princeton subject headings:
France--Boundaries--Germany--Congresses.
France--Historical geography--Congresses.
Germany--Boundaries--France--Congresses.
Germany--Historical geography--Congresses.