<http://schema.org/mainEntityofPage>
<http://aolblog.aol.com/2013/03/25/why-national-oilwell-is-ready-to-rebound-2/>
<http://www.aol.com/article/2013/03/25/why-national-oilwell-is-ready-to-rebound-2/20516759/?gen=1>