Columbia subject headings:
Catholic Church--Foreign relations--Europe--History--20th century.
Catholic Church--Foreign relations--Germany--History--20th century.
Church and state--Europe--History--20th century.
World War, 1914-1918--Catholic Church.
World War, 1939-1945--Religious aspects--Catholic Church.
Harvard subject headings:
Catholic Church--Foreign relations--Europe.
Catholic Church--Foreign relations--Germany.
Catholic Church--History--20th century.
Church and state--Europe--History--20th century.
Europe--Foreign relations--Catholic Church.
Germany--Foreign relations--Catholic Church.
World War, 1914-1918--Religious aspects--Catholic Church
World War, 1939-1945--Religious aspects--Catholic Church
Princeton subject headings:
Catholic Church--Foreign relations--Europe--History--20th century.
Catholic Church--Foreign relations--Germany--History--20th century.
Church and state--Europe--History--20th century.
World War, 1914-1918--Catholic Church.
World War, 1939-1945--Catholic Church.