Columbia subject headings:
Harvard subject headings:
Ambassadors' spouses--Europe--History--Congresses.
Diplomats' spouses--Europe--History--Congresses.
Europe--Diplomatic history--Congresses.
Princeton subject headings:
Ambassadors' spouses--Europe--History--Congresses.
Diplomats' spouses--Europe--History--Congresses.
Europe--Diplomatic history--Congresses.