Columbia subject headings:
Europe--Social conditions--Public opinion--Congresses.
Public opinion--Europe--History--18th century--Congresses.
Harvard subject headings:
Europe--Social conditions--Public opinion--Congresses.
Public opinion--Europe--History--18th century--Congresses.
Princeton subject headings:
Europe--Social conditions--Public opinion--Congresses.
Public opinion--Europe--History--18th century--Congresses.