<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://rbk.h-cdn.co/assets/cm/14/51/980x653/548f54de4b99e_-_rbk-back-pain-0514-3-s2.jpg>
<http://www.redbookmag.com/body/health-fitness/advice/g2216/how-to-stop-back-pain/>