1. Apostol, Tom M.: Project MATHEMATICS! — The Story of π — Program Guide and Workbook. Caltech, California Institute of Technology, Pasadena, CA 91125, USA, 1989.
2. Bruner, J.S.: Actual Minds, possible worlds. Cambridge, MA:Harvard University Press, 1986.
3. Chambel, T., Correia, N. and Guimarães, N.: Towards Hypervideo on the Web. IMSA’99, Third IASTED International Conference on Internet and Multimedia Systems and Applications, Nassau, Grand Bahamas, October 1999.
4. Chambel, T., and Guimarães, N.: Mechanisms for Video Integration and Navigation on the Web. WebNet’ 99 — World Conference on the WWW, Internet, & Intranet, AACE Conferences, Association for the Advancement of Computing in Education, Honolulu, HI, USA, October 1999.
5. Chambel, T., and Guimarães, N.: Aprender com Vídeo em Hipermédia. In Proceedings of CoopMedia’ 2000, Workshop de Sistemas Multimedia Cooperativos e Distribuídos, Coimbra, Portugal, Junho.