<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/54c803aa4ae7f_-_lg_9904hiwsbdiag1.gif>
<http://www.popularmechanics.com/home/outdoor-projects/how-to/a172/1275796/>