1. Chaucer, Geoffrey. The Riverside Chaucer. Ed. Larry D. Benson. 3rd edn. 1987. Oxford: Oxford University Press, 1988.
2. Aquinas, Thomas. Summa Theologiae. Ed. P. Caramello. 4 vols. Rome: Taurini, 1952–6.
3. Augustine. The City of God Against the Pagans. 7 vols. Trans. G. E. McCracken et al. Loeb Classical Library. London: Heinemann, 1957–72.
4. Avicenna. Liber de anima seu Sextus de naturalibus. Ed. Simone van Riet. Leiden: Brill, 1968.
5. Bartholomaeus Anglicus. De rerum proprietatibus. 1601. Frankfurt: Minerva, 1964.