<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/06/480x360/54cfd40858dbb_-_cycling-science-05-1212-de.jpg>
<http://www.popularmechanics.com/adventure/sports/g1034/cycling-science-7-fascinating-facts-about-bikes/>