<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/54ca6fb6b4216_-_rock-blast-4-0808-4031896.jpg>
<http://www.popularmechanics.com/home/outdoor-projects/how-to/a3443/4274976/>