1. Alberti, L. B. (1966/1435). On painting (J. R. Spencer, Trans.). New Haven, CT: Yale University Press.
2. Armstrong, D. M. (1989). Universals: An opinionated introduction. Boulder, CO: Westview Press.
3. Blumson, B. (2010). Pictures, perspective and possibility. Philosophical Studies, 149(2), 135–151.
4. Bricker, P. (1996). Isolation and unification: The realist analysis of possible worlds. Philosophical Studies, 84(2/3), 225–238.
5. Bricker, P. (2000). Island universes and the analysis of modality. In G. Preyer & F. Siebelt (Eds.), Reality and Humean supervenience: Essays on the philosophy of David Lewis. Lanham, MD: Rowman and Littlefield.