1. Accesmetrie, Website, http://www.accesmetrie.com
2. Acces City, Website, http://www.anlh.be/accescity
3. Secrétariat d’état au tourisme, Label tourisme et handicap (2001)
4. French National Comitee for Disabled People, Criteria and conditions for the attribution of the international accessibility symbol (1983)
5. GAMAH, IPP Online, http://www.ipp-online.org