위키백과, 우리 모두의 백과사전.
- “Barry Beyerstein Q&A”. 《Ask the Scientists》. Scientific American Frontiers. 2008-02-22에 확인함. "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 (3 August 1993). “Graphology Is Serious Business in France : You Are What You Write?”. 《New York Times》. 18 September 2010에 확인함.