1. Crispien, K., Petrie, H.: Providing Access to GUI’s for Blind People Using a Multimedia System. In: 95th Audio Engineering Society, New York (1993)
2. http://www.nctd.org.uk/
3. Crombie, D., Lenoir, R., McKenzie, N.: Eye of the beholder. In: EVA 2003, Institute of Archaeology, London, UK (2003)
4. http://www.ifla.org/IV/ifla65/65cp.htm
5. http://www.nfb.org