<https://www.heidirubymiller.com/2010/11/article-almost-there-or-how-heidi-ruby.html>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.heidirubymiller.com/2010/11/article-almost-there-or-how-heidi-ruby.html>