Columbia subject headings:
Holy Roman Empire--History--1517-1648--Sources.
Holy Roman Empire. Reichstag (1570 : Speyer, Germany)--History--Sources.
Harvard subject headings:
Holy Roman Empire--History--1517-1648--Sources.
Holy Roman Empire. Reichstag (1570 : Speyer, Germany)--History--Sources.
Princeton subject headings:
Holy Roman Empire--History--1517-1648--Sources.
Holy Roman Empire. Reichstag (1570 : Speyer, Germany)--History--Sources.