Columbia subject headings:
Harvard subject headings:
Migrant agricultural laborers--Europe--History.
Migrant labor--Benelux countries--History--19th century.
Migrant labor--Europe--History.
Migrant labor--Germany--History--19th century.
Princeton subject headings:
Migrant agricultural laborers--Europe--History.
Migrant labor--Benelux countries--History--19th century.
Migrant labor--Europe--History.
Migrant labor--Germany--History--19th century.