<http://schema.org/about>
"A little while ago I pointed out that China was restricting exports of rare earth elements (they aren't that rare in the Earth's crust, but because China could produce them at such a low cost, other mines around the world closed down over time). Well,"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/clean-technology/rare-earth-prices-double-on-china-restrictions.html>