1. United nations standard product and services classification (unspsc) code organization. In), http://www.unspsc.org/home.htm
2. ISO 13250. Information technology - sgml applications - topic maps(. Technical report, International Organization for Standardization, ISO/IEC 13250 (1995)
3. Abrams, D., Baecker, R., Chignell, M.H.: Information archiving with bookmarks: Personal web space construction and organization. In: Proceedings of ACM SIGCHI 1998, pp. 41–48 (1999)
4. Artale, A., Franconi, E.: A temporal description logic for reasoning about actions and plans. Journal of Artificial Intelligence Research (JAIR) 9, 463–506 (1998)
5. Artale, A., Franconi, E., Mandreoli, F.: Description logics for modelling dynamic information (1999), citeseer.nj.nec.com/570199.html