<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/54c882e20e0ce_-_workbench-step2c-0807.jpg>
<http://www.popularmechanics.com/home/how-to-plans/how-to/a1952/4219723/>