Columbia subject headings:
Monarchy--Spain--History--19th century.
Spain--Politics and government--19th century.
Harvard subject headings:
Monarchy--Spain--History--19th century--Congresses.
Spain--Politics and government--19th century--Congresses.
Princeton subject headings:
Monarchy--Spain--History--19th century--Congresses.
Spain--Politics and government--19th century--Congresses.