A. Tawfik, and E. Neufeld. Proceedings of First International Workshop on Temporal Representation and Reasoning (TIME), Pensacola, Florida, FLAIRS, (1994)
G. Figueroa, and E. Sucar. Proceedings of the Fifteenth Annual Conference on Uncertainty in Artificial Intelligence (UAI--99), page 13--20. San Francisco, CA, Morgan Kaufmann Publishers, (1999)