1. Barwise, J. and J. Perry: 1983, Situations and Attitudes, Cambridge, MA, MIT Press.
2. Chellas, B. F.: 1980, .Modal Logic. An Introduction, Cambridge University Press.
3. Gottlob, G.: 1992, ‘Complexity Results for Nonmonotonic Logics’, Journal of Logic and Computation 2(3), 397–425.
4. Grice, P.: 1975, ‘Logic and Conversation’, in P. Cole and J. Morgan (eds), Speech Acts, Syntax and Semantics III, New York, Academic Press, pp. 41–58.
5. Halpern, J. Y.: 1993, ‘Reasoning about Only Knowing with Many Agents’, in Proceedings National Conference on Artificial Intelligence (AAAI’93), pp. 655–661.