The 90-Minute Baby Sleep Program - Polly Moore My three month old really does fall asleep every 90 mins! It's crazy! The only problem is getting her to take naps longer than 30 mins grr. Anywho, I feel cheated in having bought this book. The basic explanation of sleep cycles and the whole 90 min plan could take less than two pages. But noooooo you have to buy the $12 book and slogh through all the (interesting) crap to get to the part that is basically self explanitory from the books title. Baby wakes up, add 90 min to the clock, around the 90 min mark start settling baby down, 90min, put baby down for a nap and boom! Baby's asleep. See? I just explained the whole book in a run on sentence!