1. Porter, D.: Object Lessons for the Web: Implications for Instructional Development. In: Farrell G. (ed.): The Commonwealth of Learning (COL): The Changing Faces of Virtual Education (2001) 47–70.
2. IEEE Information Technology-Learning Technology-Learning Objects Metadata (P1484.12), Learning Object Metadata Working Draft (WD5), http://ltsc.ieee.org/doc/wg12/LOMWD63a.pdf
3. IMS Learning Resource Meta-data Information Model Version 1.2-Final Specification, http://www.imsproject.org/metadata/imsmdv1p2p1/imsmdinfov1p2p1.html
4. Dublin Core Metadata Initiative, http://purl.org/dc
5. CanCore, http://www.cancore.org