Columbia subject headings:
Poland--Economic conditions--1918-1945.
Poland--Emigration and immigration--Government policy--History.
Poland--Emigration and immigration--History.
Polish people--Foreign countries--History.
Harvard subject headings:
Poland--Economic conditions--1918-1945
Poland--Emigration and immigration--Government policy--History.
Poland--Emigration and immigration--History.
Polish people--Foreign countries--History.
Princeton subject headings: