<https://3.bp.blogspot.com/-QGO2lbrQSRs/WXRquusAv7I/AAAAAAAAg4M/-jceRiPhNYwuyHYaauMQlqvh-cssun1uACLcBGAs/s640/grandparents-1969824_640.jpg>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://hetmoederfront.com/emancipatie-1-van-de-belangrijkste-redenen-om-grootouders-in-te-schakelen/>