<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/54ca6fb64071d_-_rock-blast-3-0808-83483975.jpg>
<http://www.popularmechanics.com/home/outdoor-projects/how-to/a3443/4274976/>