<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/640x393/54cab5c0162f6_-_ice_rink_03_650_1210.jpg>
<http://www.popularmechanics.com/home/outdoor-projects/how-to/a6307/how-to-build-a-backyard-ice-rink/>