Columbia subject headings:
Petroleum industry and trade--Periodicals.
Petroleum industry and trade--Statistics--Periodicals.
Petroleum--Statistics--Periodicals.
Harvard subject headings:
Petroleum industry and trade--Periodicals
Petroleum industry and trade--Statistics--Periodicals
Petroleum--Statistics--Periodicals.
Princeton subject headings:
Periodicals.
Petroleum industry and trade--Periodicals.
Petroleum industry and trade--Statistics--Periodicals.
Petroleum--Statistics--Periodicals.
Statistics.