In the course of some unrelated research, I happened to notice that a portion of Chapter 12 of Brad O'Leary's 2008 book, "The Audacity of Deceit," bore a striking resemblance to an April 3, 2008 WorldNetDaily article written by Aaron Klein, entitled "Obama was 'quite religious in Islam'."
Several of Klein's articles are cited as sources by O'Leary throughout the book, and Klein is among a handful of people O'Leary thanks in the early part of his book. But there is no reference to Klein's April 3, 2008 article, either by title or web address, in either Chapter 12 or in the footnotes.
Below is a side-by-side comparison of the similar text from Klein's article and O'Leary's book. Matching text has been colored red. Not included are two embedded links in Klein's article which appear as footnotes in O'Leary's book. Additionally, one can see a distinctive misspelling of "Laotze" as "Loatze" that appeared in Klein's article is reproduced identically in The Audacity of Deceit.
Aaron Klein vs. 'The Audacity of Deceit'