Columbia subject headings:
Germany--Emigration and immigration--Government policy--History--20th century.
Germany--Emigration and immigration--Government policy--History--21st century.
Harvard subject headings:
Germany--Emigration and immigration--Government policy--History--20th century.
Germany--Emigration and immigration--Government policy--History--21st century.
Princeton subject headings:
Germany--Emigration and immigration--Government policy--History--20th century.
Germany--Emigration and immigration--Government policy--History--21st century.