<https://blogs.ethz.ch/crowdsourcing/author/d2c9e0138706afa56bbaae31703aabaf/#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://blogs.ethz.ch/crowdsourcing/author/d2c9e0138706afa56bbaae31703aabaf/>