<http://schema.org/mainEntityOfPage>
<http://www.engadget.com/2010/06/09/google-announces-caffeine-search-index-promises-50-percent-fre/True>
<http://www.engadget.com/2010/06/09/google-announces-caffeine-search-index-promises-50-percent-fre/?ncid=rss_semi>