<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef-1.bbci.co.uk/news/ws/560/amz/worldservice/live/assets/images/2014/02/14/140214115316_nguyen_cong_khe_512x288_bbc.jpg>
<http://www.bbc.com/vietnamese/vietnam/2014/02/140214_nguyencongkhe_vn_press_1979.shtml>