↑ Hansson, Sven Ove (2017). Zalta, Edward N. (penyunting). The Stanford Encyclopedia of Philosophy (ed. Summer 2017). Metaphysics Research Lab, Stanford University.
1 2 Sundholm, Göran (2014), "The Vocabulary of Epistemology, with Observations on Some Surprising Shortcomings of the English Language", Mind, Values, and Metaphysics (dalam bahasa Inggeris), Springer International Publishing, halaman 203–208, doi:10.1007/978-3-319-05146-8_13, ISBN9783319051451
