Columbia subject headings:
Harvard subject headings:
Middle Ages
Queens--Germany--History--To 1500.
Queens--Great Britain--History--To 1500.
Regency--Germany--History--To 1500.
Regency--Great Britain--History--To 1500.
Widows--Germany--History--To 1500.
Widows--Great Britain--History--To 1500.
Princeton subject headings:
Middle Ages.
Queens--Germany--History--To 1500.
Queens--Great Britain--History--To 1500.
Regency--Germany--History--To 1500.
Regency--Great Britain--History--To 1500.
Widows--Germany--History--To 1500.
Widows--Great Britain--History--To 1500.