Columbia subject headings:
Birth control.
Economic development.
Malthus, T. R. (Thomas Robert), 1766-1834.
Marx, Karl, 1818-1883.
Population.
Harvard subject headings:
Birth control.
Economic development.
Malthus, T. R. (Thomas Robert), 1766-1834.
Marx, Karl, 1818-1883
Population.
Princeton subject headings:
Birth control.
Economic development.
Malthus, T. R. (Thomas Robert), 1766-1834.
Marx, Karl, 1818-1883.
Population.