The CIA has just declassified under the Freedom of Information Act their initial look at Reverse Speech – go here for the link: CIA Library Reading Room – This posting gives David full credit for the discovery and quotes his 1991 book, Hidden Messages in Human Communication, which was released in 1991 shortly after he lectured in Washington, D.C. to the CIA, FBI, and other alphabet agencies. One must wonder, if this is what they have released, how much more do they have that they have not released yet?