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
Phanikumar CV, Maitra B. Willingness-to-pay and preference heterogeneity for rural bus attributes. J Transp Eng A-Syst. 2007 Jan;133(1).