Columbia subject headings:
Schleswig-Holstein (Germany)--Kings and rulers--Biography.
Widows--Germany--Schleswig-Holstein--Biography.
Harvard subject headings:
Schleswig-Holstein (Germany)--History--Sources--Congresses.
Schleswig-Holstein (Germany)--Kings and rulers--Biography--Congresses.
Widows--Germany--Schleswig-Holstein--Biography--Congresses.
Princeton subject headings:
Schleswig-Holstein (Germany)--Kings and rulers--Biography.
Widows--Germany--Schleswig-Holstein--Biography.