<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/768x516/54cacbf53fe24_-_treetop-trail-03-0811-xln.jpg>
<http://www.popularmechanics.com/technology/design/g593/monkeys-on-the-move-treetop-trail-lets-philadelphia-zoo-primates-go-exploring/>