<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/480x360/54cb2da12c5a6_-_aviation-mysteries-01-0314-de.jpg>
<http://www.popularmechanics.com/flight/g1460/10-unsolved-aviation-mysteries/>