<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/480x360/54cb157eeb895_-_bho-water-guns-01-0613-lgn.jpg>
<http://www.popularmechanics.com/technology/gear/g1221/a-brief-history-of-the-water-gun/>