Columbia subject headings:
Communism--Europe--History.
Marx, Karl, 1818-1883.
Socialism--Europe--History.
Harvard subject headings:
Communism--Europe--History
Marx, Karl, 1818-1883
Socialism--Europe--History
Princeton subject headings:
Communism--Europe--History.
Marx, Karl, 1818-1883.
Socialism--Europe--History.