<http://schema.org/about>
"There are some people out there who feel burning wood is inherently untreehugger-like. But when wood is burnt correctly, it can be a very effective method of heating. Other forms of heating are not without their own problems, and most rely on"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/interior-design/effective-masonry-heaters.html>