Columbia subject headings:
Catholic Church--Doctrines--History--19th century--Sources.
Catholic Church--Doctrines--History--20th century--Sources.
Christianity and politics--History--Sources.
Church and the world.
Harvard subject headings:
Catholic Church--Doctrines--History--Sources.
Christian sociology--Catholic Church--History--Sources.
Princeton subject headings:
Catholic Church--Doctrines--History--19th century--Sources.
Catholic Church--Doctrines--History--20th century--Sources.
Christianity and politics--History--Sources.
Church and the world.