1. Abelardo Morell, Camera Obscura (New York: Bulfinch Press, 2004)
2. Jim Casper, Lens Culture, 2014, audio interview
3. John Locke, An Essay Concerning Human Understanding, ed. Alexander Campbell Fraser (New York: Dover, 1959)
4. Rene Descartes, The Philosophical Writings of Descartes, trans. John Cottingham, Roben Stoothoff, and Dugald Murdoch (Cambridge: Cambridge University Press, 1985)
5. Richard Rorty, Philosophy and the Mirror of Nature (Princeton: Princeton University Press, 1979)