1. Adams, R. M. (1994). Leibniz: Determinist, Theist, Idealist. Oxford: Oxford University Press.
2. Adams, R. M. (1977). Leibniz’s theories of contingency. In Kulstad 1977, pp. 1–41.
3. Armstrong, D. (1989). A combinatorial theory of possibility. New York: Cambridge University Press.
4. Bender, S. (Forthcoming-a). Leibniz’ Metaphysik der Modalität. Berlin: De Gruyter.
5. Bender, S. (Forthcoming-b). Si omnia possibilia existerent—why Leibniz denies that all possible can exist. History of Philosophy Quarterly.