Columbia subject headings:
Agriculture--Economic aspects--United States--Statistics--Periodicals.
Exports--United States--Statistics--Periodicals.
Produce trade--United States--Statistics--Periodicals.
United States--Commerce--Statistics--Periodicals.
Harvard subject headings:
Agriculture--Economic aspects--United States--Statistics--Periodicals
Exports--United States--Statistics--Periodicals
Produce trade--United States--Statistics--Periodicals
United States--Commerce--Statistics--Periodicals.
Princeton subject headings: