<http://schema.org/mainEntityOfPage>
<http://www.upi.com/Science_News/2013/02/21/Melting-permafrost-could-be-climate-threat/83711361483762/>
<http://www.upi.com/Science_News/2013/02/21/Melting-permafrost-could-be-climate-threat/UPI-83711361483762/?pvn=1>