<http://schema.org/about>
"Trailers are such interesting exercises in design of small spaces. Pop-up campers and tent trailers have been around for a long time (see this great Pac-man version from 1936). Their great virtue is lower air  resistance when towing,"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/sustainable-product-design/pop-up-camper-looks-like-sydney-opera-house-on-wheels.html>