Columbia subject headings:
Democracy--History.
Political science--Europe--History.
Political science--United States--History.
Socialism--Europe--History.
Socialism--United States--History.
Harvard subject headings:
Democracy--History
Political science--Europe--History
Political science--United States--History
Socialism--Europe
Socialism--Europe--History
Socialism--United States
Socialism--United States--History
Princeton subject headings:
Democracy--History.
Political science--Europe--History.
Political science--United States--History.
Socialism--Europe--History.
Socialism--United States--History.