1. Herzberger, H.: 1979, Counterfactuals and consistency, Journal of Philosophy 76, 83–88.
2. Jackson, F. (ed.): 1991, Conditionals, Oxford University Press, Oxford.
3. Leblanc, H. and Wisdom, W.: 1993, Deductive Logic, 3rd edition, Prentice-Hall, Englewood Cliffs.
4. Lewis, D.: 1971, Completeness and decidability of three logics of counterfactual conditionals, Theoria 37, 74–85.
5. Lewis, D.: 1973, Counterfactuals, Harvard University Press, Cambridge, MA.