Columbia subject headings:
Europe--Economic conditions--19th century.
Europe--Economic conditions--20th century.
Europe--Social conditions--1789-1900.
Europe--Social conditions--20th century.
Harvard subject headings:
Princeton subject headings:
Europe--Economic conditions--19th century.
Europe--Economic conditions--20th century.
Europe--Social conditions--1789-1900.
Europe--Social conditions--20th century.