For most authors the prospect of their books sending readers to sleep would be horrifying. But the latest publishing phenomenon topping the Amazon charts is a book that promises to do just that, at least for children.The Rabbit Who Wants to Fall Asleep, has been created by Swedish behavioural psychologist and linguist Carl-Johan Forssen Ehrlin and is outselling Harper Lee's Go Set a Watchman and Paula Hawkins' The Girl on the Train.The 26-page paperback, the first self-published work to top the Amazon charts, uses positive reinforcement and other psychological techniques to help children relax, focus and eventually drift off.Parents are instructed to yawn frequently, emphasise certain words and speak in a slow and calm voice when reading words in italics. Although it has pictures, children are asked to just listen rather than read.The bestseller has been translated into seven languages.Forssen Ehrlin said it was "the verbal equivalent of rocking a baby to sleep" and hundreds of online reviews from parents claim it has revolutionised bedtimes."I had written books before about leadership and personal development using these techniques, but I got the idea for a children's book while I was driving on a long journey with my mother and she fell asleep and I got the idea of how I could use my methods to help children relax," Forssen Ehrlin said."When we stopped I wrote it all down on a napkin but it took another three-and-a-half years to come up with the perfect story so that all the techniques were used in the correct order."It helps children to focus and makes them a part of the story, so they fall asleep along with the rabbit. They meet characters like Uncle Yawn and the Heavy-Eyed Owl."Forssen Ehrlin played recordings of the book to his own child, Leon, while he was still in the womb, and now puts on the audio book to help him sleep."I'm speechless!" one parent wrote on Amazon. "I'm sitting here waiting for someone to pinch me. Bedtime just went from taking two-to-three hours to taking 12 minutes. We made it to the middle of page 2."Another said: "Had my boy yawning in about three minutes and fast asleep in 10."The book has been translated into seven languages.Forssen Ehrlin is planning a follow-up that will help children learn how to use the toilet."I am amazed how successful it has been," he said. "My e-mail inbox is full of messages from parents who say it has helped their children to relax and fall asleep."Alison Forrestal, director of books and entertainment media for Amazon UK, said: "This book has been a word-of-mouth phenomenon. Carl-Johan published independently and has now reached parents and children all over the UK."This is the first time an independent author has taken the No1 position in our print-books chart and The Rabbit Who Wants to Fall Asleep is outselling big releases such as Go Set a Watchman."It's a great achievement and we hope there are many more books to come."The book was published using Amazon's CreateSpace system...