Cox, Catherine M. The Early Mental Traits of 300 Geniuses. Genetic Studies of Genius Volume 2. Stanford (CA): Stanford University Press. 1926. (原始内容存档于2016-03-03) 使用|archiveurl=需要含有|url= (帮助). 简明摘要 (2 June 2013).使用|accessdate=需要含有|url= (帮助)
Cox, Catherine M. The Early Mental Traits of 300 Geniuses. Genetic Studies of Genius Volume 2. Stanford (CA): Stanford University Press. 1926. (原始内容存档于2016-03-03) 使用|archiveurl=需要含有|url= (帮助). 简明摘要 (2 June 2013).使用|accessdate=需要含有|url= (帮助)