<https://cppmag.com/2019/12/29/quang-ha-trong-vang-khi-solo-vi-sao-khong-the-ma-thieu-le-quyen/#person-admin>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://cppmag.com/2019/12/29/quang-ha-trong-vang-khi-solo-vi-sao-khong-the-ma-thieu-le-quyen/>