Columbia subject headings:
Catholic Church--Europe--History--20th century.
Church and state--Europe--History--20th century.
Europe--Church history--20th century.
Pius XII, Pope, 1876-1958.
Harvard subject headings:
Catholic Church--Europe--History--20th century.
Church and state--Europe--History--20th century.
Europe--Church history--20th century.
Pius XII, Pope, 1876-1958.
Princeton subject headings:
Catholic Church--Europe--History--20th century.
Church and state--Europe--History--20th century.
Europe--Church history--20th century.
Pius XII, Pope, 1876-1958.