<https://blog.nonnguyen.com/2019/11/tai-sao-hacker-lai-thich-linux-hon.html>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://blog.nonnguyen.com/2019/11/tai-sao-hacker-lai-thich-linux-hon.html>