1. Blackburn, P., de Rijke, M., Venema, Y.: Modal logic. Cambridge Tracts in Theoretical Computer Science, book 53. Cambridge University Press (2002)
2. Boolos, G.: The Logic of Provability. Cambridge University Press, Cambridge (1993)
3. Carnap, R.: Introduction to Symbolic Logic and its Applications. Dover Publications, Mineola (1958)
4. Chagrov, A., Zakharyaschev, M.: Modal logic. Oxford Logic Guides, vol. 35. The Clarendon Press, Oxford University Press New York (1997)
5. Church, A.: Introduction to mathematical logic. Princeton Landmarks in Mathematics. Princeton University Press (1996)