<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://www.popularmechanics.com/technology/g1348/7-unbelievable-rube-goldberg-machines-we-love/>
<http://www.popularmechanics.com/technology/g1348/7-unbelievable-rube-goldberg-machines-we-love/>