Columbia subject headings:
Ethnicity.
Europe--Race relations.
Migrant labor--Europe.
Occupations and race.
Race relations.
Harvard subject headings:
Ethnicity.
Europe--Race relations.
Migrant labor--Europe.
Occupations and race.
Race relations.
Princeton subject headings:
Ethnicity.
Europe--Race relations.
Migrant labor--Europe.
Occupations and race.
Race relations.