<http://schema.org/about>
"More than 13 million passengers used Amtrak's rail service in the first six months of the company's 2010 fiscal year, putting the company on track to break an a"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/green-tech/transportation/stories/amtrak-on-target-to-break-ridership-record>