<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/320x240/54cb2436ce31f_-_brief-history-sleds-09-1213-lgn.jpg>
<http://www.popularmechanics.com/adventure/sports/g1377/a-brief-history-of-the-sled/>