Columbia subject headings:
Petroleum industry and trade--Caspian Sea Region.
Petroleum industry and trade--Middle East.
Petroleum--Transportation--Caspian Sea Region.
Petroleum--Transportation--Middle East.
Harvard subject headings:
Petroleum industry and trade--Caspian Sea Region
Petroleum industry and trade--Middle East
Petroleum--Transportation--Caspian Sea Region.
Petroleum--Transportation--Middle East.
Princeton subject headings:
Petroleum industry and trade--Caspian Sea Region.
Petroleum industry and trade--Middle East.
Petroleum--Transportation--Caspian Sea Region.
Petroleum--Transportation--Middle East.