<https://3dprintingindustry.com/news/are-you-ready-for-this-4d-printing-is-on-the-way-5990/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://3dprintingindustry.com/news/are-you-ready-for-this-4d-printing-is-on-the-way-5990/>