<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/15/40/640x320/landscape-1443718034-step-3.jpg>
<http://www.popularmechanics.com/home/outdoor-projects/how-to/a7670/how-to-build-this-backyard-swing-set/>