Allen, Warren (2008). "The Structure of Gould". A Warren Allen et al. Stephen Jay Gould: Reflections on His View of Life. Oxford: Oxford University Press, p. 24, 59.
Prum, R.O., & Brush, A.H. (Març 2003). "Which Came First, the Feather or the Bird?" Scientific American, vol.288, no.3, pp.84-93. Traducció al castellà a Investigación y ciencia, maig 2003 "Origen y evolución de la pluma"
Maynard Smith, John (1995). "Genes, Memes, & Minds".The New York Review of Books 42 (Nov. 30): 46–48. "By and large, I think their [Spandrels] paper had a healthy effect [...] Their critique forced us to clean up our act and to provide evidence for our stories. But adaptationism remains the core of biological thinking." Una valoració similar es troba a l'article escrit per Ernst Mayr al 1983 "How to Carry Out the Adaptationist Program?" The American Naturalist 121 (3): 324–334; and George C. Williams, Natural Selection: Domains, Levels, and Challenges. Nova York: Oxford University Press. 1992.
Wolpert, L. i A. Richards (1998) A Passion For Science. Oxford: Oxford University Press, pp 139-152. [[Especial: BookSources/0198542127|ISBN 0-19-854212-7]]