1. Clark, R.E. & Estes, F. (March–April, 1999). The Development of Authen- tic Educational Technologies.Educational Technology, 30(2), 5–16.
2. Collis, B. & Strjker. (2001). New pedagogies and re-usable learning ob- jects: Toward a new economy in education.Journal of Educational Technology Systems, 30(2), 137–157.
3. Dean, P. (1995). Examining the practice of human performance technol- ogy.Performance Improvement Quarterly, 8 (2), 68–94.
4. Dickelman, G.J. (2000). EDIT 797: Performance-based design [Online], http://pcd-innovations.com/EDIT797/id98_m.htm.
5. Douglas, I. (2001). Instructional design based on reusable learning ob- jects: applying lessons of object-oriented software engineering to learning systems design. IEEE Frontiers in Education Conference, Reno, Nevada, October, F4E 1-5.