1. R. Fagin, J. Y. Halpern, and M. Y. Vardi, A model-theoretic analysis of knowledge: preliminary report, Proceedings of the 25th IEEE Symposium on Foundations of Computer Science,1984, pp. 268–278; also appears as IBM RJ 4373.
2. J. Y. Halpern and Y. Moses, Knowledge and common knowledge in a distributed environment, Proceedings of the 3rd ACM Symposium on Principles of Distributed Computing,1984, pp. 50–61; a revised version appears as IBM RJ 4421.
3. J. Y. Halpern and Y. Moses, A guide to modal logics of knowledge, to appear as an IBM RJ, 1985.
4. J. Hintikka, Knowledge and Belief, Cornell University Press, 1962.
5. G. E. Hughes and M. J. Cresswell, An Introduction to Modal Logic, Methuen, London, 1968.