<https://secure.gravatar.com/avatar/c740093e2cd73a2cacd158dccfc520dd?s=96&amp;d=mm&amp;r=g>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.prostruct.nl/tu-delft-voert-numerus-fixus-in-voor-bouwkunde/>