<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ghk.h-cdn.co/assets/cm/15/11/320x408/54ff53ae4daf5-new-treehouses-book-phmpjc-lg.jpg>
<http://www.goodhousekeeping.com/home/g1116/amazing-treehouses/>