Columbia subject headings:
Germany--Foreign relations--Poland.
Germany--History--1517-1648.
Poland--Foreign relations--Germany.
Poland--History--Vladislaus IV Sigismund, 1632-1648.
Władysław IV Zygmunt, King of Poland, 1595-1648.
Harvard subject headings:
Germany--Foreign relations--Poland.
Germany--History--1517-1648.
Poland--Foreign relations--Germany
Poland--History--Vladislaus IV Sigismund, 1632-1648
Władysław IV Zygmunt, King of Poland, 1595-1648.
Princeton subject headings:
Europe--History--1517-1648.
Holy Roman Empire--History--1517-1648.
Poland--History--1573-1795.
Władysław IV Zygmunt, King of Poland, 1595-1648.