1. Negation as Failure
2. L. Console, and P. Torasso, 1990 . Integrating models of the correct behavior into abductive diagnosis . Proceedings of the 9th European Conference on Artificial Intelligence, Stockholm, Sweden, pp.160 -166 .
3. Hypothetical Reasoning in Causal Models
4. 1989 . A theory of diagnosis for incomplete causal models . Proceedings of the 11th International Joint Conference on Artificial Intelligence, Detroit, MI, pp.1311 -1317 .