<https://crystal-verry.com/#website>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://crystal-verry.com/%E3%82%AB%E3%83%AB%E3%82%BB%E3%83%89%E3%83%8B%E3%83%BC%E7%99%BD%E3%81%84%E9%B3%A5%E3%80%80%E5%A4%A9%E7%84%B6%E7%9F%B3>