You will find that not even a month ago this very topic was asked here in the forum.
http://www.dakkadakka.com/dakkaforum/posts/list/450956.page
Couldn't hurt to do a search next time
Anyways read the linked thread and your question shall be answered.
Automatically Appended Next Post: Cheexsta wrote:Weird, the AU site still has it, but the US one doesn't. Try eBay or the Dakka trade forum. Actual GW stores or independents might still have them in stock, too.
The book is still available in the
UK and AU, not the US.