United States. Children's Bureau and Lundberg, Emma O. (Emma Octavia), 1881-1954. A Social Study of Mental Defectives in New Castle County, Delaware, Dependent, Defective, and Delinquent Classes Series No. 3, Bureau Publication No. 24 , Washington, D.C: Government Printing Office, 1917, https://fraser.stlouisfed.org/title/8317, accessed on December 30, 2025.