<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ghk.h-cdn.co/assets/cm/15/11/55000779cc853-mattress-shopping-2-5q0ba5-orig-master-1.jpg>
<http://www.goodhousekeeping.com/home-products/a25695/mattress-buying-guide/?src=shelter_footer>