<https://www.cereal.nl/blog/tips-voor-een-stressvrije-ochtend-begin-je-dag-met-rust-en-balans/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.cereal.nl/blog/tips-voor-een-stressvrije-ochtend-begin-je-dag-met-rust-en-balans/>