<http://schema.org/url>
<http://www.treehugger.com/sustainable-product-design/witold-rybczynski-on-the-four-paradigms-of-american-cities.html>
<http://www.treehugger.com/sustainable-product-design/witold-rybczynski-on-the-four-paradigms-of-american-cities.html>