<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://wdy.h-cdn.co/assets/cm/15/09/54eb03dc0a065_-_5-surprising-premenstrual-effects-mdn.jpg>
<http://www.womansday.com/health-fitness/womens-health/a2552/5-surprising-premenstrual-effects-119538/>