Columbia subject headings:
Harvard subject headings:
Agricultural laborers--Mexico
Agricultural laborers--United States
Agriculture and state--Mexico.
Agriculture and state--United States.
Mexico--Foreign economic relations--United States.
Produce trade--Government policy--Mexico.
Produce trade--Government policy--United States
United States--Foreign economic relations--Mexico.
Princeton subject headings:
Agricultural laborers, Foreign--United States--Congresses.
Agriculture--Mexico--Congresses.
Agriculture--United States--Congresses.
Mexico--Foreign economic relations--United States--Congresses.
United States--Foreign economic relations--Mexico--Congresses.