Columbia subject headings:
Harvard subject headings:
Political science--Europe--History--Congresses.
Political science--Europe--Philosophy--Congresses.
Reason of state--Congresses.
State, The--Congresses
Princeton subject headings:
Political science--Europe--History--Congresses.
Political science--Europe--Philosophy--History--Congresses.
Reason of state--Congresses.
State, The--Congresses.