<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/480x360/54cb16c58ca2c_-_infrasound-03-0713-lgn.jpg>
<http://www.popularmechanics.com/science/environment/g1246/5-things-we-can-learn-from-sounds-we-cant-hear/>