Harper William L.. A sketch of some recent developments in the theory of conditionals. Ifs, Conditionals, belief, decision, chance, and time, edited by Harper William L., Stalnaker Robert, and Pearce Glenn, The University of Western Ontario series in philosophy of science, vol. 15, D. Reidel Publishing Company, Dordrecht, Boston, and London, 1981, pp. 3–38.Stalnaker Robert C.. A theory of conditionals. A reprint of XLVII 470. Ifs, Conditionals, belief, decision, chance, and time, edited by Harper William L., Stalnaker Robert, and Pearce Glenn, The University of Western Ontario series in philosophy of science, vol. 15, D. Reidel Publishing Company, Dordrecht, Boston, and London, 1981, pp. 41–55.Lewis David. Counterfactuals and comparative possibility. Ifs, Conditionals, belief, decision, chance, and time, edited by Harper William L., Stalnaker Robert, and Pearce Glenn, The University of Western Ontario series in philosophy of science, vol. 15, D. Reidel Publishing Company, Dordrecht, Boston, and London, 1981, pp. 57–85. (Reprinted from Journal of philosophical logic, vol. 2 (1973), pp. 418–446; also reprinted in Contemporary research in philosophical logic and linguistic semantics, Proceedings of a conference held at the University of Western Ontario, London, Canada, edited by D. Hockney, W. Harper, and B. Freed, The University of Western Ontario series in philosophy of science, vol. 4, D. Reidel Publishing Company, Dordrecht and Boston 1975, pp. 1–29.)Stalnaker Robert C.. A defense of conditional excluded middle. Ifs, Conditionals, belief, decision, chance, and time, edited by Harper William L., Stalnaker Robert, and Pearce Glenn, The University of Western Ontario series in philosophy of science, vol. 15, D. Reidel Publishing Company, Dordrecht, Boston, and London, 1981, pp. 87–104.