<https://secure.gravatar.com/avatar/f5e422e70998631260884bdde50e7e2e?s=96&amp;d=wp_user_avatar&amp;r=g>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://depresenteerschool.nl/blog/drie-tips-korte-presentatie/>