<https://freebit.cz/kazmo-takhle-ne-podminky-souteze-se-meni-za-zady-soutezicich/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://freebit.cz/kazmo-takhle-ne-podminky-souteze-se-meni-za-zady-soutezicich/>