Columbia subject headings:
Harvard subject headings:
Foreign workers--Germany--Societies, etc.--History.
Germany--Emigration and immigration--Social aspects--History.
Immigrants--Germany--Societies, etc.--History.
Princeton subject headings:
Foreign workers--Germany--Societies, etc.--History.
Germany--Emigration and immigration--Social aspects--History.
Immigrants--Germany--Societies, etc.--History.