Columbia subject headings:
Thirty Years' War, 1618-1648--Congresses.
Harvard subject headings:
Church and state--Europe--Congresses.
Europe--History--1492-1648--Congresses.
Holy Roman Empire--History--1517-1648--Congresses.
Thirty Years' War, 1618-1648--Causes--Congresses.
Princeton subject headings:
Church and state--Europe--Congresses.
Europe--History--1492-1648--Congresses.
Holy Roman Empire--History--1517-1648--Congresses.
Thirty Years' War, 1618-1648--Causes--Congresses.