<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/54caa00ba4f96_-_solarplaneinthesky_400_0410.jpg>
<http://www.popularmechanics.com/flight/a5551/solar-powered-plane-potential/>