<https://forum.usa.info.pl/topic/32045-czy-mo%C5%BCliwe-s%C4%85-loty-do-usa-po-szczepieniu/page/5/#comment-317437>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://forum.usa.info.pl/topic/32045-czy-mo%C5%BCliwe-s%C4%85-loty-do-usa-po-szczepieniu/page/5/?tab=comments#comment-317439>