Columbia subject headings:
Monarchy--Russia.
Olga, Queen, consort of George I, King of the Hellenes, 1851-1926.
Queens--Greece--Biography.
Harvard subject headings:
Olga, Queen, consort of George I, King of the Hellenes, 1851-1926.
Queens--Greece--Biography.
Princeton subject headings:
Olga, Queen, consort of George I, King of the Hellenes, 1851-1926.
Queens--Greece--Biography.