Columbia subject headings:
Rhine River Valley--History.
Spain--Foreign relations--1621-1665.
Thirty Years' War, 1618-1648.
Harvard subject headings:
Rhine River Valley--History
Spain--Foreign relations--1621-1665.
Thirty Years' War, 1618-1648.
Princeton subject headings:
Rhine River Valley--History.
Spain--Foreign relations--1621-1665.
Thirty Years' War, 1618-1648.