Columbia subject headings:
Harvard subject headings:
Emigration and immigration law--United States.
Foreign workers--United States
Mexican Americans
Mexico--Relations--United States--Congresses.
United States--Relations--Mexico--Congresses.
Princeton subject headings:
Emigration and immigration law--United States.
Foreign workers--United States.
Mexican Americans.
Mexico--Relations--United States--Congresses.
United States--Relations--Mexico--Congresses.