위키백과, 우리 모두의 백과사전.
- Barry Beyerstein Q&A. 《Ask the Scientists》. Scientific American Frontiers. 2008년 2월 22일에 확인. "they simply interpret the way we form these various features on the page in much the same way ancient oracles interpreted the entrails of oxen or smoke in the air. I.e., it's a kind of magical divination or fortune telling where 'like begets like.'"
- James, Barry, "Graphology Is Serious Business in France : You Are What You Write?", 3 August 1993 작성. 18 September 2010 확인.