In 1975, Geller published his first autobiography, "My Story", and acknowledged that, in his early career, his manager talked him into adding a magic trick to make his performances last longer. This trick involved Geller appearing to guess audience members' car registration numbers, when his manager had given them to him ahead of time. One of Geller's most prominent critics was the sceptic James Randi, who accused Geller repeatedly of trying to pass off magic tricks as paranormal displays. Randi wrote the book "The Truth About Uri Geller" challenging Geller's claims, and often duplicated Geller's performances using stage magic techniques.