Columbia subject headings:
Harvard subject headings:
Agricultural laborers--United States--Congresses.
Foreign workers--United States--Congresses.
Migrant labor--United States--Congresses.
Seasonal labor--United States--Congresses.
Princeton subject headings:
Agricultural laborers--United States--Congresses.
Foreign workers--United States--Congresses.
Migrant labor--United States--Congresses.
Seasonal labor--United States--Congresses.