1. Artosi, A., Benassi, P., Governatori, G., Rotolo, A.: Shakespearian modal logic: A labelled treatment of modal identity. In: Kracht, M., de Rijke, M., Wansing, H., Zakharyaschev, M. (eds.) Advances in Modal Logic, vol. 1, pp. 1–21. CSLI Publications, Stanford (1998)
2. Artosi, A., Governatori, G., Rotolo, A.: Labelled tableaux for non-monotonic reasoning: Cumulative consequence relations. Journal of Logic and Computation 12(6), 1027–1060 (2002)
3. Chellas, B.: Modal Logic: An Introduction. Cambridge University Press, Cambridge (1980)
4. D’Agostino, M., Mondadori, M.: The taming of the cut. Journal of Logic and Computation 4, 285–319 (1994)
5. Fagin, R., Halpern, J.Y., Moses, Y., Vardi, M.Y.: Reasoning about Knowledge. MIT Press, Cambridge (1995)