1. Article 29 Data Protection Working Party (2007) Opinion 4/2007 on the concept of personal data. (01248/07/EN WP 136) http://ec.europa.eu/justice_home/fsj/privacy/docs/wpdocs/2007/wp136_en.pdf
2. Article 29 Data Protection Working Party (2005) Working document on data protection issues related to RFID technology. (10107/05/EN WP 105). http://ec.europa.eu/justice_home/fsj/privacy/docs/wpdocs/2005/wp105_en.pdf , last accessed 02.07.2007
3. Article 29 Data Protection Working Party (2004) Opinion on more harmonised information provisions. (11987/04/EN-WP 100). http://ec.europa.eu/justice_home/fsj/privacy/
4. Bauer M, Meints M, Hansen M (eds) (2005) Structured overview on prototypes and concepts of identity management systems, Future of Identity in the Information Society (FIDIS) Deliverable D3.1. http://www.fidis.net
5. Beslay L, Hakala H (2003) Digital territory: bubbles. (draft version available at http://cybersecurity.jrc.es/docs/DigitalTerritoryBubbles.pdf ), last accessed on 02.07.2007