<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/54ca640c664a6_-_hammer_drills_11_0211-xl.jpg>
<http://www.popularmechanics.com/home/tools/reviews/g140/11-hammer-drill-comparison-test/>