<http://schema.org/alternativeHeadline>
"About 40 percent of California's greenhouse gases come from vehicles, and the state's new rules also aim to stimulate production of so-called zero-emission vehicles."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/green-tech/transportation/stories/california-proposes-rules-to-spur-clean-car-growth>