Columbia subject headings:
Agricultural education--United States.
Agriculture and state--United States.
Agriculture--Research--United States.
Agriculture--United States.
Food supply--United States.
Harvard subject headings:
Agricultural education--United States.
Agriculture and state--United States.
Agriculture--Research--United States
Agriculture--United States
Food supply--United States
Princeton subject headings:
Agricultural education--United States.
Agriculture and state--United States.
Agriculture--Research--United States.
Agriculture--United States.
Food supply--United States.