<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/768x516/54ca995c0c742_-_bicycle_helmet_470-1209-xln.jpg>
<http://www.popularmechanics.com/adventure/sports/g253/4339919/>