Some background: In the New Vegas quest 'Oh My Papa' one of the ways to convince the Great Khan faction to break an alliance is either by a speech check, or finding a certain book that the Great Khans can use as a guide when their leader eventually passes on.

That book is titled "Pretty, Pretty Horsies: A History of The Mongol Empire."
Make of that what you will.

Unfortunately this is not an image-mod for the game.

Yet.