Columbia subject headings:
Agricultural laborers, Foreign--Government policy--United States.
Agricultural laborers--Government policy--United States.
Foreign workers certification--United States.
Migrant agricultural laborers--Government policy--United States.
Harvard subject headings:
Agricultural laborers, Foreign--Government policy--United States.
Agricultural laborers--Government policy--United States.
Foreign workers certification--United States.
Migrant agricultural laborers--Government policy--United States.
Princeton subject headings:
Agricultural laborers, Foreign--Government policy--United States.
Agricultural laborers--Government policy--United States.
Foreign workers certification--United States.
Migrant agricultural laborers--Government policy--United States.