1. Ausserhofer, A. (1999). Web-Based Teaching and Learning: A Panacea?, IEEE Communications, Volume 37, Number 3, pp. 92–96, March 1999.
2. de Bra, P. & Calvi, L. (1998). AHA: A Generic Adaptive Hypermedia System, Second Workshop on Adaptive Hypertext and Hypermedia, at the Ninth ACM Conference on Hypertext and Hypermedia, pp. 5–11. Pittsburgh, USA, June 20–24, 1998.
3. Brusilovsky, P. & Anderson, J. (1998). ACT-R electronic bookshelf: An adaptive system for learning cognitive psychology on the Web, WebNet 98 World Conference of the WWW, Internet & Intranet, pp. 92–97, Orlando, Florida, November 7–12, 1998.
4. Carro, R.M., Pulido, E. & Rodríguez, P. (1999). TANGOW: Task-based Adaptive learNer Guidance On the Web, 2nd Workshop on Adaptive Systems and User Modeling on the Web at the Eight International WWW Conference. Toronto, Canada, May 11–14, 1999.
5. da GraÇa, M., Benedito, J., Pontin R. (1998). Tools for Authoring and Presenting Structured Teaching Material in the WWW, WebNet 98 World Conference of the WWW, Internet & Intranet, pp. 194–199, Orlando, Florida, November 7–12, 1998.