<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/06/54d0e972b36da_-_pmx0606hd006_large.jpg>
<http://www.popularmechanics.com/home/how-to-plans/how-to/a685/how-to-build-a-patio-easily/>