1. Abiteboul, S., Hull, R., and Vianu, V. (1995). Foundations of databases. Addison-Wesley, New York, NY.
2. Anderson, A. R. and Belnap, N. D. (1975). Entailment — the logic of relevance and necessity, volume 1. Princeton University Press, Princeton, NJ.
3. Belkin, N. J. (1981). Ineffable concepts in information retrieval. In Sparck Jones, K., editor, Information retrieval experiment, pages 44–58. Butterworths, London, UK.
4. Belnap, N. D. (1977). How a computer should think. In Ryle, G., editor, Contemporary aspects of philosophy, pages 30–56. Oriel Press, Stocksfield, UK.
5. Borgida, A. (1995). Description logics in data management. IEEE Transactions on Data and Knowledge Engineering, 7(5):671–682.