<https://mustang.ir/questions/#primaryimage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://mustang.ir/questions/question/%D8%A2%D9%BE%D9%84%D9%88%D8%AF-%D9%81%D8%A7%DB%8C%D9%84-%D8%AF%D8%B1-php>