<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/54caad441ceb0_-_garage-door-operator-de.jpg>
<http://www.popularmechanics.com/home/outdoor-projects/how-to/a6041/garage-door-opener-how-it-works/>