<https://frontera.ru/forums/topic/4567-%D0%BA%D0%BE%D0%BB%D0%B4%D1%83%D0%BD/#comment-55427>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://frontera.ru/forums/topic/4567-%D0%BA%D0%BE%D0%BB%D0%B4%D1%83%D0%BD/>