Columbia subject headings:
Agricultural pests--Government policy--United States.
Foreign trade regulation--United States.
Plant diseases--Government policy--United States.
Plant inspection--Government policy--United States.
Harvard subject headings:
Agricultural pests--Government policy--United States.
Foreign trade regulation--United States.
Plant diseases--Government policy--United States.
Plant inspection--Government policy--United States.
Princeton subject headings:
Agricultural pests--Government policy--United States.
Foreign trade regulation--United States.
Plant diseases--Government policy--United States.
Plant inspection--Government policy--United States.