<https://laptrinhcanban.com/cpp/lap-trinh-cpp-co-ban/gioi-thieu-ngon-ngu-cpp/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://laptrinhcanban.com/cpp/lap-trinh-cpp-co-ban/gioi-thieu-ngon-ngu-cpp/>