Columbia subject headings:
Catholic Church--History--20th century.
Catholic Church--Ireland--History--20th century.
Christian union--Catholic Church.
Christian union--Ireland.
Church and social problems--Catholic Church.
Church and social problems--Ireland.
Ireland--Church history--20th century.
Harvard subject headings:
Christian union--Catholic Church
Christian union--Ireland.
Princeton subject headings:
Catholic Church--History--20th century.
Catholic Church--Ireland--History--20th century.
Christian union--Catholic Church.
Christian union--Ireland.
Church and social problems--Catholic Church.
Church and social problems--Ireland.
Ireland--Church history--20th century.