Columbia subject headings:
Migrant agricultural laborers--Canada.
Migrant agricultural laborers--Mexico.
Temporary employment--Canada.
Temporary employment--Mexico.
Harvard subject headings:
Migrant agricultural laborers--Canada.
Migrant agricultural laborers--Mexico.
Temporary employment--Canada.
Temporary employment--Mexico.
Princeton subject headings:
Migrant agricultural laborers--Canada.
Migrant agricultural laborers--Mexico.
Temporary employment--Canada.
Temporary employment--Mexico.