I picked the book up in Medford OR. for $3. It's called "Find the Ace" by Leo Behnke. It goes over several routines including a few sleights to make sure even if they guess the right card (and it is MUCH easier to try and guess than to believe your eyes!) they still lose. Here's a link.
http://www.magicity.com/product_info...c942beccf7dc5a
I was on a bus in Seattle years back and a guy got on and approached these two teenagers. He pulled out three cards and a notebook to work them on. Needless to say by the next bus stop the teenagers were out $20 and the guy got off at the next stop. I knew the trick back then and watched in disbelief as they fell for the game.
He used a particularly devious method that is covered in "Find the Ace" wherein the con artist "accidently" puts a crimp in the money card and then removes it secretly and crimps another card so the players think they have an unfair advantage when in fact they were conned again.
Despite the illicit uses available with the three card monte it is an amazing and entertaining routine for a magician. "Find the Ace" covers it in a more magicians oriented manner but like any sleight it could be used for evil!