Columbia subject headings:
Catholic Church--Germany--History--19th century--Congresses.
Catholic Church--Germany--History--20th century--Congresses.
Christianity and culture--History--19th century--Congresses.
Christianity and culture--History--20th century--Congresses.
Germany--Church history--19th century--Congresses.
Germany--Church history--20th century--Congresses.
Harvard subject headings:
Catholic Church--Germany--History--19th century.
Catholic Church--Germany--History--20th century.
Christianity and culture--History.
Princeton subject headings:
Catholic Church--Germany--History--19th century.
Catholic Church--Germany--History--20th century.
Christianity and culture--19th century.
Christianity and culture--20th century.
Germany--Church history--19th century.
Germany--Church history--20th century.