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