3 books in series

The Legend of Korra: The Art of the Animated Series

The Legend of Korra: The Art of the Animated Series is a 3-book series with 3 released primary works first released in 2013 with contributions by Michael Dante DiMartino and Bryan Konietzko.

The Legend of Korra: The Art of the Animated Series--Book One: Air
The Legend of Korra: The Art of the Animated Series Book Two: Spirits
The Legend of Korra: The Art of the Animated Series--Book Four: Balance