Columbia subject headings:
Catholic Church--Doctrines--History--20th century.
Protestant churches--Doctrines--History--20th century.
Theology, Doctrinal--History--20th century.
Harvard subject headings:
Catholic Church--Doctrines--History--20th century.
Catholic Church--Doctrines--History--History--20th century.
Theologians.
Theology, Doctrinal--History--20th century.
Theology, Protestant--History--20th century.
Princeton subject headings: