1. Advanced Distributed Learning (ADL). Sharable Content Object Reference Model (SCORM ® ) 2004 Overview (2004), retrieved July 7, 2005 from http://www.adlnet.org
2. ARIADNE Alliance of remote instructional authoring & distribution networks for Europe (2004), retrieved July 7, 2005, http://ariadne.unil.ch
3. Bradshaw, J.M.: An introduction to software agents. In: Bradshaw, J.M. (ed.) Software Agents. MIT Press, Massachusetts (1997)
4. CanCore - Canadian Core About (2004), Retrieved from July 7, 2005, http://www.cancore.ca/about.html
5. Downes, S.: Learning objects: resources for distance education worldwide. In: International Review of Research in Open and Distance Learning 2(1) (2001)