1. Balbiani, P., Fariñas del Cerro, L., Herzig, A.: Declarative semantics for modal logic programs. In: Proceedings of the 1988 International Conference on Fifth Generation Computer Systems, pp. 507–514. ICOT (1988)
2. Baldoni, M., Giordano, L., Martelli, A.: A framework for a modal logic programming. In: Joint International Conference and Symposium on Logic Programming, pp. 52–66. MIT Press, Cambridge (1996)
3. Cresswell, M.J., Hughes, G.E.: A New Introduction to Modal Logic. Routledge, New York (1996)
4. Debart, F., Enjalbert, P., Lescot, M.: Multimodal logic programming using equational and order-sorted logic. Theoretical Comp. Science 105, 141–166 (1992)
5. Demri, S.: The complexity of regularity in grammar logics and related modal logics. Journal of Logic and Computation 11(6), 933–960 (2001)