Columbia subject headings:
Harvard subject headings:
Europe--Ethnic relations.
Germany--Relations--Poland.
Immigrants--Germany--Social conditions
Immigrants--Poland--Social conditions.
Minorities--Germany--Social conditions.
Minorities--Poland--Social conditions.
Poland--Relations--Germany
Princeton subject headings:
Europe--Ethnic relations.
Germany--Relations--Poland.
Immigrants--Germany--Social conditions.
Immigrants--Poland--Social conditions.
Minorities--Germany--Social conditions.
Minorities--Poland--Social conditions.
Poland--Relations--Germany.