Columbia subject headings:
Europe--Boundaries--History.
Europe--Civilization.
Europe--History.
Geopolitics--Europe--History.
Territory, National--Europe.
Harvard subject headings:
Europe--Boundaries--History.
Europe--Civilization.
Europe--History.
Geopolitics--Europe--History.
Territory, National--Europe.
Princeton subject headings:
Europe--Boundaries--History.
Europe--Civilization.
Europe--History.
Geopolitics--Europe--History.
Territory, National--Europe.