Columbia subject headings:
Germany--Emigration and immigration--Government policy.
Poland--Emigration and immigration--Government policy.
Refugees--Government policy--Germany.
Refugees--Government policy--Poland.
Harvard subject headings:
Germany--Emigration and immigration--Government policy.
Poland--Emigration and immigration--Government policy.
Princeton subject headings:
Germany--Emigration and immigration--Government policy.
Poland--Emigration and immigration--Government policy.
Refugees--Government policy--Germany.
Refugees--Government policy--Poland.