<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/480x360/54cb00200f215_-_historic-guns-04-1112-lgn.jpg>
<http://www.popularmechanics.com/military/weapons/g1002/the-11-most-important-guns-in-history/>