1. Getting it out of our system;Nelson,1967
2. Hypertext & Hypermedia: Theory and Application;Woodhead,1991
3. Towards a psychophysics of hypermedia;Fischer,1990
4. Authoring and evaluation of hypermedia for education;Hutchings;Computers Educ.,1992
5. Discussion: formal and informal learning with hypermedia;Duchastel,1990