1. Anderson, A. and Belnap, N.: 1975, Entailment: The Logic of Relevance and Necessity. Princeton University Press, Princeton, NJ.
2. Ballard, D.: 1986. Cortical connections and parallel processing: structure and function. The Behavioral and Brain Sciences 9(1) 67?90.
3. Barton, G. E., Berwick, R. and Ristad, E.: 1987, Computational Complexity and Natural Language. MIT Press, Cambridge, MA.
4. Brachman, R.: 1983, What is-a is and isn't: an analysis of taxonomic links in semantic networks. IEEE Computer 16(10): 30?36.
5. Brachman, R. and Levesque, H.: 1984, The tractability of subsumption in frame-based description languages. In AAAI-84, pages 34?37, Austin, TX.