Columbia subject headings:
Foreign workers--Germany.
Migrant labor--Germany.
Migrant labor--Poland.
Harvard subject headings:
Agricultural laborers--Poland.
Foreign workers--Germany--History.
Germany--Emigration and immigration.
Migrant agricultural laborers--Germany.
Poland--Emigration and immigration
Seasonal labor--Germany.
Seasonal labor--Poland.
Princeton subject headings:
Foreign workers--Germany.
Migrant labor--Germany.
Migrant labor--Poland.