1. 1. Adam Smith, quoted in I. I. Rubin, A History of Economic Thought (London: Ink Links, 1979), p. 169.
2. 3. Leon Trotsky, Permanent Revolution, Results and Prospects (New York: Pathfinder Press, 1969), pp. 276-279.
3. 4. Vladimir I. Lenin, A Characterization of Economic Romanticism: Sismondi & Our Native Sismondists (Moscow: Progress, 1967), pp. 71-72.
4. 5. Karl Marx to P. V. Annenkov and to J. B. Schweizer, in The Poverty of Philosophy (Moscow: Progress, 1975), pp. 165-187.