<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/54ca6f21f1c70_-_3inventions-2-0808-39267193.jpg>
<http://www.popularmechanics.com/science/green-tech/a3384/4273679/>