<https://www.aquamagazine.com/news/pool-hot-tub-alliance-news/article/15542201/pool-hot-tub-alliance-begins-revision-of-phta16-standard>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.aquamagazine.com/news/pool-hot-tub-alliance-news/article/15542201/pool-hot-tub-alliance-begins-revision-of-phta16-standard>