Columbia subject headings:
Agricultural productivity--Statistics--Periodicals.
Agriculture--Economic aspects--Statistics--Periodicals.
Food supply--Statistics--Periodicals.
Produce trade--Statistics--Periodicals.
Harvard subject headings:
Agricultural productivity--Statistics--Periodicals.
Agriculture--Economic aspects--Statistics--Periodicals
Food supply--Statistics--Periodicals.
Produce trade--Statistics--Periodicals
Princeton subject headings:
Agriculture--Statistics--Periodicals.
Periodicals.
Statistics.