<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ghk.h-cdn.co/assets/16/15/640x320/landscape-1460476688-jastrow-illusion.jpg>
<http://www.goodhousekeeping.com/life/entertainment/news/a37862/toy-train-track-optical-illusion/>