Columbia subject headings:
Communism.
Darwin, Charles, 1809-1882.
Evolution.
Marx, Karl, 1818-1883.
Harvard subject headings:
Darwin, Charles, 1809-1882
Marx, Karl, 1818-1883
Social Darwinism.
Princeton subject headings:
Darwin, Charles, 1809-1882.
Marx, Karl, 1818-1883.
Social Darwinism.