Book of the Weeping Angels

The Book of the Weeping Angels was a book written about the Weeping Angels.

History
On Alfava Metraxis in the 51st century, River Song found a book about the Weeping Angels. She gave it to the Doctor, who skimmed through it. The Doctor commented that it was slow in the middle and asked River if she also did not like the man's girlfriend. He then noticed that something was wrong. He questioned why there were no images, to which River replied that the "image of an Angel, is itself an Angel". This alerted the Doctor to the fact the video that had been recorded of the Angel was a danger. (DW: The Time of Angels)