<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/54ca69ef9c34c_-_diggers_01_0810-lg.jpg>
<http://www.popularmechanics.com/science/environment/g211/extreme-digging-machine-pictures/>