Columbia subject headings:
Germans--United States--History.
Germany--Emigration and immigration--History--20th century.
Social sciences--Research--Europe--History--20th century.
Social sciences--Research--United States--History--20th century.
United States--Emigration and immigration--History--20th century.
Harvard subject headings:
Germans--United States--History.
Germany--Emigration and immigration--History--20th century.
Social sciences--Research--Europe--History--20th century.
Social sciences--Research--United States--History--20th century.
United States--Emigration and immigration--History--20th century.
Princeton subject headings: