Erlendir vefir
AAMR American Association on Mental Retardation
Frambu - Senter for sjeldne funktionshemninger
National Organization for Rare Disorders, Inc.
Nordspes
National Library of Medicine - PubMed
The Arc of the United States - A national organization on mental retardation
The Psychological Corporation - A Hardcourt Company
Leit
Stjórnborð
