Columbia subject headings:
Catholic Church--Doctrines--History--20th century.
Catholic Church--Germany--History--20th century.
Germany--Church history--20th century.
Theologians--Germany.
Theology--History--20th century.
Harvard subject headings:
Catholic Church--Doctrines--History--20th century.
Catholic Church--Germany--History--20th century.
Church and the world--History of doctrines--20th century.
Germany--History--1918-1933.
Princeton subject headings: