Columbia subject headings:
Harvard subject headings:
Byzantine Empire--History--Constantine XI Dragases, 1448-1453
Istanbul (Turkey)--History--Siege, 1453
Turkey--History--Mehmed II, 1451-1481
Princeton subject headings:
Byzantine Empire--History--Constantine XI Dragases, 1448-1453.
Istanbul (Turkey)--History--Siege, 1453.
Turkey--History--Mehmed II, 1451-1481.