<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/54ca75e0e1e3a_-_05-circulating-tumor-cell-chip-470-1108.jpg>
<http://www.popularmechanics.com/science/a3724/4286850/>