Self-published picture book sensation is acquired by Penguin Random House

A Swedish psychologist's self-published picture book about a sleep-deprived rabbit has been acquired by Penguin Random House after becoming a word-of-mouth sensation.

A new edition of Carl-Johan Forssén Ehrlin's "The Rabbit Who Wants To Fall Asleep" will come out in paper in the U.S. and the U.K. on Oct. 2 and as an e-book Sept. 8, the publisher told The Associated Press on Wednesday.

Billed as a groundbreaking story that "gives suggestions to the child's unconscious mind to sleep," Ehrlin's book features such soporific helpers as Uncle Yawn and Sleepy Snail and has inspired an international debate over its effectiveness. "The Rabbit Who Wants To Fall Asleep" was illustrated by Irina Maununen.

Originally released in 2011 and translated into English by Ehrlin a year ago, the book this summer soared into the top 10 on and Barnes &, at times outselling such high-profile works as Harper Lee's "Go Set a Watchman" and E L James' "Grey."

"It is an absolute joy for me to see the response that the book has received from parents all around the world, and it is something I never imagined would happen," Ehrlin, 37, said in a statement. "I frequently hear from parents about how the story has helped ease their child's bedtime and naptime routines, and I am so pleased to know that the book will now be able to reach, and help, even more families."

Ehrlin also plans two more books with Penguin Random House; their content will be announced at a later date.

"The Rabbit Who Wants to Fall Asleep" will be published by Random House Children's Books in the U.S. and by Penguin Random House Children's U.K. Two audio editions also will come out on Oct. 2, one narrated by a man, the other by a woman.