Columbia subject headings:
Africa--Foreign economic relations--United States.
Agricultural productivity--Africa.
Agricultural subsidies--United States.
Agriculture and state--Africa.
United States--Foreign economic relations--Africa.
Harvard subject headings:
Africa--Foreign economic relations--United States.
Agricultural productivity--Africa.
Agricultural subsidies--United States.
Agriculture and state--Africa.
United States--Foreign economic relations--Africa.
Princeton subject headings:
Africa--Foreign economic relations--United States.
Agricultural productivity--Africa.
Agricultural subsidies--United States.
Agriculture and state--Africa.
United States--Foreign economic relations--Africa.