Smith, Tara (2005). «Peikoff, Sylvan Leonard (1933- )». I: Shook, John R. The Dictionary of Modern American Philosophers. London: Thoemmes Continuum, bd. 4, s. 1889. ISBN1-84371-037-4. OCLC53388453.
Smith, Tara (2006). Ayn Rand's Normative Ethics: The Virtuous Egoist. New York: Cambridge University Press, s. 6. ISBN0-521-86050-4. OCLC60971741. Sitat: «...an authoritative source of [Rand's] views».
Younkins, Edward W. (2007). Champions of a Free Society: Ideas of Capitalism's Philosophers and Economists. Lanham, Maryland: Lexington Books, s. 201. ISBN0-7391-2647-4. OCLC228676591. Sitat: «...authoritatively described and systematically explained».
Gladstein, Mimi Reisel (1999). The New Ayn Rand Companion. Westport, Connecticut: Greenwood Press, s. 105. ISBN0-313-30321-5. OCLC40359365. Sitat: «The reader who wants a comprehensive view of orthodox Objectivism as it has evolved since Rand's death should start with Peikoff's book».
Kelley, David (2000). The Contested Legacy of Ayn Rand: Truth and Toleration in Objectivism. New Brunswick, New Jersey: Transaction Publishers, s. 108. ISBN0-7658-0863-3. OCLC44727861.
