<https://definebrush.com>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://definebrush.com/en/blogs/news/%E6%96%B0%E3%83%96%E3%83%A9%E3%83%B3%E3%83%89-define-brush-%E3%83%87%E3%83%93%E3%83%A5%E3%83%BC>