On 1 May 2007 it was announced that New York-based Turtle Pond Publications and Berlin Zoo had signed a deal for the worldwide publishing rights to Knut with the hopes of raising global warming issues. Written by Craig Hatkoff and his daughters, the 44-page book entitled "Knut, der kleine Eisbärenjunge" ("Little Polar Bear Knut") is about Knut's life story as well as photographs. Although books about Knut had already been published in Germany, this book was the first to be authorized by the Berlin Zoo.