Columbia subject headings:
Catholic Church--France--History--20th century--Congresses.
Church history--20th century--Congresses.
Protestant churches--Germany--History--20th century--Congresses.
Harvard subject headings:
Catholic Church--France--History--20th century--Congresses.
Church history--20th century--Congresses.
Protestant churches--Germany--History--20th century--Congresses.
Princeton subject headings: