Columbia subject headings:
Harvard subject headings:
Jews--Germany--History.
Jews--Migrations.
Princeton subject headings:
Foreign workers, German--History.
Foreign workers--Germany--History.
Germans--Foreign countries--History--19thcentury.
Germans--Foreign countries--History--20thcentury.
Germany--Emigration and immigration--History--19th century.
Germany--Emigration and immigration--History--20th century.
Refugees--Germany--History.