<https://forum.beobuild.rs/threads/pvc-i-alu-stolarija-iskustva-i-preporuke.3074/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://forum.beobuild.rs/threads/pvc-i-alu-stolarija-iskustva-i-preporuke.3074/page-76>