<https://secure.gravatar.com/avatar/e2e7d2c40428dac8e3daa2f5224be0cf?s=96&amp;d=mm&amp;r=g>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://gentlysallim.com/%EC%BB%B4%ED%93%A8%ED%84%B0/%EC%9A%B0%ED%9A%8C-ip/>