Columbia subject headings:
Eastern question.
Espionage--Turkey--History.
Spies--Great Britain--Biography.
Turkey--History--Ottoman Empire, 1288-1918.
Vámbéry, Ármin, 1832-1913.
Harvard subject headings:
Eastern question.
Espionage--Turkey--History.
Spies--Great Britain--Biography.
Turkey--History--19th century.
Turkey--History--Ottoman Empire, 1288-1918.
Vámbéry, Ármin, 1832-1913.
Princeton subject headings:
Espionage--Turkey--Biography--Personal narratives--Sources.
Personal narratives.
Spies--Great Britain--Biography--Personal narratives--Sources.
Turkey--History--19th century.
Turkey--History--Ottoman Empire, 1288-1918.
Vámbéry, Ármin, 1832-1913--Biography--Personal narratives--Sources.