<https://secure.gravatar.com/avatar/c0f452c9c562e8ac2ab4677ace8e468d?s=96&amp;r=g>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://ahaslides.com/de/blog/complete-guide-to-open-ended-questions-with-examples/>