<http://schema.org/mainEntityOfPage>
<http://www.upi.com/Health_News/2011/10/02/Purple-potatoes-lower-blood-pressure/15601317612770/>
<http://www.upi.com/Health_News/2011/10/02/Purple-potatoes-lower-blood-pressure/UPI-15601317612770/?rel=91811326413538>