<https://blogs.library.leiden.edu/fb-video/docs/manual-videoportal-university-leiden/advanced-video-settings/replace-video/#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://schema.org/WebPage>
<https://blogs.library.leiden.edu/fb-video/docs/manual-videoportal-university-leiden/advanced-video-settings/replace-video/>