Columbia subject headings:
Christianity--Denmark--History--To 1500.
Denmark--History--To 1241.
Denmark--Kings and rulers--Biography.
Harald I Blue Tooth, King of Denmark, approximately 910-985.
Vikings--Denmark--Biography.
Harvard subject headings:
Princeton subject headings:
Christianity--Denmark--History--To 1500.
Denmark--History--To 1241.
Denmark--Kings and rulers--Biography.
Harald I Blue Tooth, King of Denmark, approximately 910-985.
Vikings--Denmark--Biography.