1. National Association for Down Syndrome. Facts about Down syndrome. http://www.nads.org/pages_new/facts.html (2008). Accessed 25 Dec 2012
2. Black, B., Wood, A.: Utilising information communication technology to assist the education of individuals with Down syndrome. Down syndrome Issues and Information (2003)
3. Kirijian, A., Myers, M.: Web fun central: online learning tools for individuals with Down syndrome. In: Lazar, J. (ed.) Universal Usability: Design Computer Interfaces for Diverse Users, pp. 195–230. Wiley, Chichester (2007)
4. Wishart, J.G.: Learning in young children with Down’s syndrome: developmental trends. In: Rondal, J.A., Perera, J., Nadel, L., Comblain, A. (eds.) Down’s Syndrome Psychological Psychobiological and Socio-Educational Perspectives, pp. 81–96. Whurr, London (1996)
5. Belmont, J.M.: Medical-behavioral research in retardation. In: Ellis, N.R. (ed.) International Review of Research in Mental Retardation, pp. 181–196. Academic Press, New York (1971)