Columbia subject headings:
Harvard subject headings:
Cities and towns--Switzerland--History--Congresses.
City planning--Switzerland--Fribourg--History--Congresses.
Fribourg (Switzerland)--History--Congresses.
Princeton subject headings:
City planning--Switzerland--Fribourg--Congresses.
Fribourg (Switzerland)--Civilization--Congresses.
Fribourg (Switzerland)--History--Congresses.