<http://schema.org/image_url>
"http://media.al.com/wire/photo/tim-cook-27d00c71ba8ebf8d.jpg"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.al.com/business/index.ssf/2013/04/apple_issues_17_billion_in_deb.html>