Columbia subject headings:
Harvard subject headings:
Holy Roman Empire--History--To 1517--Congresses.
Holy Roman Empire--Kings and rulers--Congresses.
Legitimacy of governments--Congresses.
Poland--History--To 1572--Congresses.
Poland--Kings and rulers--Congresses.
Royal houses--Holy Roman Empire--Congresses.
Princeton subject headings:
Holy Roman Empire--History--To 1517.
Holy Roman Empire--Kings and rulers.
Legitimacy of governments.
Poland--History--To 1572.
Poland--Kings and rulers.
Royal houses--Holy Roman Empire.