Duxbury – www.duxburysystems.com

American Printing House – www.aph.org

Royal National Institute for the Blind (RNIB) – www.rnib.org.uk

World Blind Union (WBU) – www.wbu.com

International Council on English Braille (ICEB) – www.iceb.org

International Council for Education of People With Visual Impairment (ICEVI) – www.icevi.org

Perkins School for the Blind, USA – www.perkins.org