Puddledancer Press is the premier publisher of books and articles about Nonviolent Communication since 1998. They also produce a free monthly newsletter with articles about NVC.
Since 2004, PuddleDancer has donated more than 80,000 books to individuals and organizations in need around the globe. They also have a monthly special that is worth checking out.
You can also find these books on Amazon, bookstores and your local libraries.