1. Ackerman, Jennifer (2017). The Genius of Birds, Penguin Books.
2. Adams, Robert Merrihew (1999). Finite and Infinite Goods: A Framework for Ethics, Oxford University Press.
3. Anderson, Elizabeth (1995). Value in Ethics and Economics, Harvard University Press.
4. Andersson, Henrik, and Herlitz, Anders (2022). Value Incommensurability: Ethics, Risk, and Decision-Making, Routledge.
5. the Fathers of the English Dominican Province (1920). The Summa Theologiae of St. Thomas Aquinas, [2nd and rev. ed.]. Available online: https://www.newadvent.org/summa/.