Columbia subject headings:
Harvard subject headings:
France--Relations--Germany--Congresses.
France--Relations--Switzerland--Congresses.
Germany--Relations--France--Congresses.
Germany--Relations--Switzerland--Congresses.
Switzerland--Relations--France--Congresses.
Switzerland--Relations--Germany--Congresses.
Princeton subject headings:
France--Relations--Germany--Congresses.
France--Relations--Switzerland--Congresses.
Germany--Relations--France--Congresses.
Germany--Relations--Switzerland--Congresses.
Switzerland--Relations--France--Congresses.
Switzerland--Relations--Germany--Congresses.