1. Department for Education and Skills (2005 )e-Strategy Harnessing Technology: transforming learning and children's services. http://www.dfes.gov.uk/publications/e-strategy/.
2. M. Keiren(2004 )Developing e-Portfolio's with the Blackboard Content System (release 2.0). Report of Edutrip 2004. http://www.edusite.nl/edutrip2004/verslagen_teaching/13701.
3. G. Roberts, W. Aalderink, J. Cook, M. Feijen, J. Harvey, S. Lee, and V. P. Wade(2005 )Reflective learning, future thinking: digital repositories, e-portfolios, informal learning and ubiquitous computing. ALT/SURF/ILTA Spring Conference Research Seminar. Dublin, Ireland, Trinity College. http://e-learning.surf.nl/docs/portfolio/alt_surf_ilta_white_paper_2005.pdf.
4. K. Slotman, P. Fisser, M. Gulmans, C. Braspenning, J. Van der veen, and H. Logtenberg(2005 )Digitaal portfolio - de hype voorbij of optimisme zonder grenzen?[Digital portfolio - hype or cause for boundless optimism?] (Utrecht, Stichting Surf).