1. Chavez, A., and Maes, P. 1996. Kasbah: An agent marketplace for buying and selling goods. In First Int. Conf. On the Practical Application of Intelligent Agents and Multi-Agent Technology, London, UK, 1996
2. Choi, S-Y., Stahl D. and Whinston, A., 1997. The economics of electronic commerce, MacMillan, Indianapolis, USA, 1997.
3. Dignum, F. 1999. Autonomous agents with norms. In AI & Law, vol.7, pp.69–79, 1999.
4. Dignum, F., Verharen, E. and Bos, S. 1997. Implementation of a cooperative agent architecture based on the language-action perspective. In M. Singh et.al. (eds.)-Proc. Of the fourth Int. workshop on Agent Theories, Architectures and Languages (ATAL-97), Providence, USA, 1997.
5. Doorenbos, B., Etzioni, O. and Weld, D. 1996. A scalable comparison-shopping agent for the World Wide Web. Technical report TR96-01-03, University of Washington, 1996.