Columbia subject headings:
Harvard subject headings:
Baghdad Railway--History.
Eastern question.
Germany--Foreign relations--Turkey.
Petroleum industry and trade--Political aspects--Germany--History.
Petroleum industry and trade--Political aspects--Middle East--History.
Railroads--Middle East--History.
Turkey--Foreign relations--Germany.
Princeton subject headings:
Germany--Foreign economic relations--Turkey.
Petroleum industry and trade--Political aspects--Iraq.
Railroads--Turkey.
Turkey--Foreign economic relations--Germany.