Columbia subject headings:
Harvard subject headings:
Christianity and other religions--Europe--Islam--Congresses.
Church and state--Europe--History--19th century--Congresses.
Church and state--Europe--History--20th century--Congresses.
Europe--Church history--19th century--Congresses.
Europe--Church history--20th century--Congresses.
Islam--Europe--Relations x Christianity--Congresses.
Princeton subject headings:
Europe--Religion--19th century--Congresses.
Europe--Religion--20th century--Congresses.
Religion and state--Europe--History--19th century--Congresses.
Religion and state--Europe--History--20th century--Congresses.
Religious pluralism--Europe--History--19th century--Congresses.
Religious pluralism--Europe--History--20th century--Congresses.