Further discussions:
Paul Lepanto, Return to Reason: An Introduction to Objectivism (Smithtown, New York: Exposition Press, 1971), pp. 84-89.
Leonard Peikoff, Objectivism: The Philosophy of Ayn Rand (New York: Dutton, 1991), pp. 403-405.
George Reisman, Capitalism: A Treatise on Economics (Ottawa, Illinois: Jameson Books, 1996), pp. 357-358.
David Harriman, ed., Journals of Ayn Rand (New York: Dutton, 1997), pp. 420-421.