Columbia subject headings:
Harvard subject headings:
Democracy
Habermas, Jürgen
Marx, Karl, 1818-1883
Revolutions and socialism.
Utopias.
Princeton subject headings:
Habermas, Jürgen--Contributions in political science.
Marx, Karl, 1818-1883.
Socialism--Philosophy--History.
Utopian socialism--Philosophy--History.