Ask any parent about the bedtime rituals she uses to get her kids to sleep and you'll likely get an earful — stories involving books, stuffed animals, songs, back-scratching, bath time, more books, and possibly a nightcap or two (for the parent!) I'm not sure why sleep is so hard for most kids to master, but it is. And when kids don't sleep, mom and dad don't sleep either.

So you could imagine why a book that promises to put kids to sleep quickly and painlessly might be taking the parental-world by storm. Better still, author Carl-Johan Forssen Ehrlin not only makes that promise, but his legions of fans have confirmed it via glowing reviews on Facebook, Amazon, and word-of-mouth reviews.

Here's one from Facebook user Stacy Blakeley:

"Ok so I've seen a few posts about this book over the last week. Checked out the reviews on amazon and there wasn't any bad ones.. so tonight I settled down on the landing outside my girls bedrooms with my kindle and by the time I had finished they were asleep. In a matter of 20 mins. Instead of hours upon hours of in and out of bed and crying. I could sit here and weep tears of joy. Thank you."

Or this review from Amazon user, Ms. Rs Aniff

"I'm actually speechless! I'm sat [sic] here waiting for someone to pinch me. Bedtime just went from taking 2-3 hours to taking 12mins. We made it to the middle of page 2."

"The Rabbit Who Wants to Fall Asleep" is the #1 selling book on Amazon U.K. right now, beating out top sellers "Go Set a Watchman" by Harper Lee and Paula Hawkins' 'The Girl on The Train."

So how does it work? "Rabbit" is not your average children's book. Forssen Ehrlin is a college communications professor in Sweden who calls the story "the verbal equivalent of rocking a baby to sleep." Parents are instructed to yawn frequently, use their child's name within the story, and speak in a slow and calm voice when reading words in italic.

As parents read, children are introduced to characters such as Uncle Yawn and the Heavy-Eyed Owl. Uncle Yawn, the world's kindest wizard, helps rabbits fall asleep using a magic sleeping powder, while the Heavy-Eyed Owl delivers a form of guided meditation, helping kids relax and drift off.

Put it all together and "The Rabbit Who Wants To Fall Asleep" is the stuff that dreams are made of.