Curtis Rod, Freitag Per, LaGuardia James J, Thornton Steven, Vicari Sandra, Markwell Stephen
Division of Developmental Disabilities, Department of Psychiatry, Southern Illinois University School of Medicine, Springfield, 32702, USA.
Public Health Rep. 2004 Jul-Aug;119(4):396-400. doi: 10.1016/j.phr.2004.05.003.