I have the first copy of it that came into the US. Ted Lesley gave it to me. I was amazed at how unclear it was. I wish he'd given me the German version, instead.
The best way to do this, though, is in a book by Robert Parrish and Oscar Weigle called Do That Again!
It's called "The Direct Divination." It was the subject of some controversy over at the "green place" a few years ago when, as an April Fool's gag, someone had posted that I had devised a No Fishing word diviniation method. The joke was on them, because I posted about this idea, and told people I was under a special agreement not to release the material.
Eventually the people who perpetrated the joke were banned from the green place.
Since the controversy is over, I'll 'splain it here.
Imagine this. A spectator thinks of a word. He writes it down, you reveal the word. You could do the same thing with a birthday.
Here's the method:
This appears on page 17 of Parrish and Weigle's "..do that again" as "The Direct Divination."
"As soon as the person has written, step up to him and grasp him by the collar in such a way that the thumb presses on his jugular vein. Bring your head close to his, 'to establish telepathic contact,' and hiss, 'Tell me what you wrote or I'll choke hell out of you!'
"This you proceed to do unless he follows your instructions. In fact, it is best to kill the man anyway, thus leaving you clean at the finish.
"The success of this trick depends on selecting a man smaller than yourself."