<https://www.sprucecareeradvisors.com/post/2016/04/19/go-right-no-go-left-no-go-straight-but-dont-stay-put>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.sprucecareeradvisors.com/post/2016/04/19/go-right-no-go-left-no-go-straight-but-dont-stay-put>