Columbia subject headings:
Catholic Church--Doctrines--History.
Catholic labor unions--Italy--History.
Church and social problems--Italy--Catholic Church--History.
Labor--Religious aspects--Christianity--Italy--History.
Harvard subject headings:
Catholic Church--Doctrines--History.
Catholic labor unions--Italy--History.
Church and social problems--Italy--Catholic Church--History.
Labor--Italy--Religious aspects--Christianity--History.
Labor--Religious aspects--Christianity--Italy--History.
Princeton subject headings:
Catholic Church--Doctrines--History.
Catholic labor unions--Italy--History.
Church and social problems--Italy--Catholic Church--History.
Labor--Religious aspects--Christianity--Italy--History.