Columbia subject headings:
Harvard subject headings:
Catholic Church--Customs and practices--History--Congresses.
Power (Social sciences)--Europe--History--Congresses.
Rites and ceremonies--Europe--History--Congresses.
Rites and ceremonies--Social aspects--Europe--History--Congresses.
Princeton subject headings:
Rites and ceremonies--Europe--History--Congresses.
Rites and ceremonies--Social aspects--Congresses.