Vekeman F, Gauthier-Loiselle M, Faust E, Lefebvre P, Lahoz R, Duh MS, Sacco P. Patient and caregiver burden associated with fragile x syndrome in the United States. Am J Intellect Dev Disabil. 2015 Sep;120(5):444-59. doi: 10.1352/1944-7558-120.5.444
Hartman M, Bolton E, Fehnel SE. Accounting for age differences on the Wisconsin Card Sorting Test: decreased working memory, not inflexibility. Psychol Aging. 2001 Sep 1;16(3):385-99.