Columbia subject headings:
Empresses--Europe--Biography.
Princes--Europe--Biography.
Queens--Europe--Biography.
Regents--Europe--Biography.
Harvard subject headings:
Empresses--Europe--Biography.
Princesses--Europe--Biography.
Queens--Europe--Biography
Regents--Europe--Biography.
Princeton subject headings:
Empresses--Europe--Biography.
Princesses--Europe--Biography.
Queens--Europe--Biography.
Regents--Europe--Biography.