CRAW, S. and BOSWELL, R. 1999. Representing problem-solving for knowledge refinement. In Proceedings of the 16th American Association for Artificial Intelligence national conference on artificial intelligence (AAAI-99), co-located with the 11th Annual conference on innovative applications of artificial intelligence (IAAI-99), 18-22 July 1999, Orlando, USA. Palo Alto: AAAI Press, pages 227-234.