Alongside T-shirts, Bart has been included in various other "The Simpsons"-related merchandise, including air fresheners, baseball caps, bumper stickers, cardboard standups, refrigerator magnets, key rings, buttons, dolls, posters, figurines, clocks, soapstone carvings, Chia Pets, bowling balls and boxer shorts. "The Bart Book", a book about Bart's personality and attributes, was released in 2004. Other books include "Bart Simpson's Guide to Life". "", which is not an official publication, includes a chapter analyzing Bart's character and comparing him to the "Nietzschean ideal".