Columbia subject headings:
Catholic League, 1609-1648--Congresses.
Protestant Union (1608-1621)--Congresses.
Harvard subject headings:
Catholic League, 1609-1648--Congresses.
Europe--Church history--17th century--Congresses.
Germany--Church history--17th century--Congresses.
Protestant churches--History--Congresses.
Reformation--Germany--Congresses.
Thirty Years' War, 1618-1648--Religious aspects--Congresses.
Princeton subject headings:
Catholic League, 1609-1648--Congresses.
Europe--Church history--17th century--Congresses.
Germany--Church history--17th century--Congresses.
Protestant churches--History--Congresses.
Reformation--Germany--Congresses.
Thirty Years' War, 1618-1648--Religious aspects--Congresses.