<http://schema.org/mainEntityOfPage>
<http://www.upi.com/Science_News/2013/03/01/Population-growth-seen-as-species-threat/65151362185436/>
<http://www.upi.com/Science_News/2013/03/01/Population-growth-seen-as-species-threat/UPI-65151362185436/?spt=hs&or=sn>