<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/640x415/54cabb53753c2_-_biomass_02_0111-de-33442817.jpg>
<http://www.popularmechanics.com/home/how-to/a6499/is-wood-the-best-renewable-fuel-for-heating/>