Columbia subject headings:
Animal industry--United States--Statistics--Periodicals.
Meat industry and trade--United States--Statistics--Periodicals.
Pork industry and trade--United States--Statistics--Periodicals.
Swine--United States--Statistics--Periodicals.
Harvard subject headings:
Animal industry--United States--Statistics--Periodicals.
Meat industry and trade--United States--Statistics--Periodicals.
Pork industry and trade--United States--Statistics--Periodicals.
Princeton subject headings: