“Princess of Mars large” by Art by Frank E. Schoonover, photographed by “Mars book covers: Science Fiction & Fantasy” on Flickr – http://www.flickr.com/photos/44823747@N02/4816903503/in/set-72157625110973004. Licensed under Public domain via Wikimedia Commons – http://commons.wikimedia.org/wiki/File:Princess_of_Mars_large.jpg#mediaviewer/File:Princess_of_Mars_large.jpg