<https://secure.gravatar.com/avatar/0e991d62916e33f57737084538f5dfe8?s=96&amp;d=mm&amp;r=g>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.apf.ruhr-uni-bochum.de/lehre/mastermodule_wiwi/ascm/>