Columbia subject headings:
Catholic Church--Teaching office--History of doctrines--20th century.
Christian ethics--Catholic authors--History--20th century.
Church--History of doctrines--20th century.
Harvard subject headings:
Catholic Church--Teaching office--History of doctrines--20th century.
Christian ethics--Catholic authors--History--20th century.
Church--History of doctrines--20th century
Princeton subject headings: