Columbia subject headings:
Ferdinand I, Holy Roman Emperor, 1503-1564--Correspondence.
Germany--History--Charles V, 1519-1556--Sources.
Germany--History--Ferdinand I, 1556-1564--Sources.
Harvard subject headings:
Ferdinand I, Holy Roman Emperor, 1503-1564--Correspondence.
Germany--History--Charles V, 1519-1556--Sources.
Germany--History--Ferdinand I, 1556-1564--Sources.
Princeton subject headings:
Ferdinand I, Holy Roman Emperor, 1503-1564--Correspondence.
Germany--History--Charles V, 1519-1556--Sources.
Germany--History--Ferdinand I, 1556-1564--Sources.