Columbia subject headings:
Harvard subject headings:
Brain drain--Europe--History--20th century.
Europe--Emigration and immigration--History--20th century.
Intellectuals--United States--History--20th century.
Learning and scholarship--United States--History--20th century.
United States--Emigration and immigration--History--20th century.
Princeton subject headings:
Brain drain--Europe--History--20th century.
Europe--Emigration and immigration--History--20th century.
Intellectuals--United States--History--20th century.
Learning and scholarship--United States--History--20th century.
United States--Emigration and immigration--History--20th century.