Board Thread:Questions and Answers/@comment-90.207.192.174-20140930172716/@comment-24033490-20141027152907

Wikia text:

"A book called «Sword Art Online: End World Visual Book with Special Item Attached» will be released by September 27, 2014."

If it is about this one it was released today:

http://dengekionline.com/elem/000/000/946/946842/