Columbia subject headings:
Austria--Foreign relations--Spain--Sources.
Austria--History--Ferdinand II, 1619-1637--Sources.
Habsburg, House of--History--Sources.
Spain--Foreign relations--Austria--Sources.
Spain--History--Philip IV, 1621-1665--Sources.
Thirty Years' War, 1618-1648--Diplomatic history--Sources.
Harvard subject headings:
Princeton subject headings:
Thirty Years' War, 1618-1648.