<http://schema.org/about>
"Many of us having been celebrating Earth Day for as long as we remember--but it hasn't always been this way. As evidenced by this photo from a march on the first Earth Day in 1970, it's taken the dedication, cunning, and the unflinching love of the enviro"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/slideshows/natural-sciences/11-environmentalist-heroes-an-earth-day-tribute/>