1. Destaques INE: Censos 2001 – Análise de População com Deficiência (2001), http://www.inr.pt/download.php?filename=Censos+2001&file=%2Fuploads%2Fdocs%2Finfestatistica%2FCensos2001Destaque.pdf
2. Inquérito da Universidade Lusófona sobre TV digital, http://adoptdtv.ulusofona.pt/index.php
3. WHO – Visual impairment and blindness, http://www.who.int/mediacentre/factsheets/fs282/en/
4. WHO – Priority eye diseases, http://www.who.int/blindness/causes/priority/en/index5.html
5. WHO – Blindness, http://www.who.int/topics/blindness/en/