Columbia subject headings:
Catholic Church--Doctrines--History--20th century.
Catholic Church--History--20th century.
Harvard subject headings:
Catholic Church--Doctrines--History--20th century.
Catholic Church--History--20th century.
Princeton subject headings:
Catholic Church--Doctrines--History--20th century.
Catholic Church--History--20th century.
Vatican Council (2nd : 1962-1965 : Basilica di San Pietro in Vaticano)