1D's first book debuted at number one on the Sunday Times Bestseller list. What is the books official title?

Explanation

The One Direction debut single "What Makes You Beautiful" entered the UK Singles Chart at number one selling a total number of 153.965 copies in its first week. Addionally it smashed the pre-order sales record at One Directions label Sony Music. Their debut album "Up All Night" was with 468.000 copies the 16th biggest selling album of 2011 in the UK.