Columbia subject headings:
Harvard subject headings:
East Europeans--Germany--Ruhr (Region)--History--Exhibitions.
Foreign workers--Germany--Ruhr (Region)--History--Exhibitions.
Immigrants--Germany--Ruhr (Region)--Social conditions--Exhibitions.
Jews--Germany--Ruhr (Region)--Migrations--Exhibitions.
Ruhr (Germany : Region)--Emigration and immigration--Exhibitions.
Social integration--Germany--Ruhr (Region)--History--Exhibitions.
Princeton subject headings:
East Europeans--Germany--Ruhr (Region)--History--Exhibitions.
Europe, Eastern--Emigration and immigration--History--Exhibitions.
Foreign workers--Germany--Ruhr (Region)--History--Exhibitions.
Immigrants--Germany--Ruhr (Region)--Social conditions--Exhibitions.
Jews--Germany--Ruhr (Region)--History--Exhibitions.
Ruhr (Germany : Region)--Emigration and immigration--History--Exhibitions.
Social integration--Germany--Ruhr (Region)--History--Exhibitions.