<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef-1.bbci.co.uk/news/560/media/images/71682000/jpg/_71682522_p6800355-coloured_ultrasound_scan_of_a_womb_showing_twins-spl.jpg>
<http://www.bbc.com/news/health-25337953>