Columbia subject headings:
Harvard subject headings:
Europe--Politics and government--19th century--Congresses.
Political science--Europe--Philosophy--History--19th century--Congresses.
State, The--History--19th century--Congresses.
Princeton subject headings:
Europe--Politics and government--19th century--Congresses.
Political science--Europe--Philosophy--History--19th century--Congresses.
State, The--History--19th century--Congresses.