<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/15/47/1447790515-8-nasa-neutral-buoyancy-laboratory-astronaut-training.jpg>
<http://www.popularmechanics.com/technology/design/g3/10-incredibly-cool-swimming-pools/>