Thomas Aquinas, Summa Theologica, Part 1, Question 12, Article 1, Objection 1. Translated by Fathers of the English Dominican Province. Accessed online August 13, 2024; URL: http://www.freecatholicebooks.com/books/summa.pdf
Corrigan, Kevin; Harrington, L. Michael (2023), "Pseudo-Dionysius the Areopagite", in Zalta, Edward N.; Nodelman, Uri (eds.), The Stanford Encyclopedia of Philosophy (Summer 2023 ed.), Metaphysics Research Lab, Stanford University, retrieved 2024-08-18