M. Sahami, S. Dumais, D. Heckerman, and E. Horvitz. Learning for Text Categorization: Papers from the 1998 Workshop, Madison, Wisconsin, AAAI Technical Report WS-98-05, (1998)
M. Sheeran, and G. St\aalmarck. Proceedings 2nd Intl.\ Conf.\ on Formal Methods in
Computer-Aided Design, FMCAD'98, Palo Alto, CA, USA,
4--6 Nov 1998, Springer-Verlag, Berlin, (1998)