Columbia subject headings:
Harvard subject headings:
Baghdad Railway--History--20th century.
Colonies--History--20th century.
Eastern question (Balkan)
Petroleum--History--20th century.
World War, 1914-1918--Influence
Princeton subject headings:
Baghdad Railway--History--20th century.
Colonies--History--20th century.
Eastern question (Balkan)
Petroleum--History--20th century.
World War, 1914-1918--Influence.