[1]XML Topic Maps (XTM) 1.0 (2005-10-25 23:11:49 +09:00 版) <http://www.topicmaps.org/xtm/1.0/xtm1-20010806.html>

[2] ISO 13250-2: Topic Maps — Data Model (2008-06-04 22:00:09 +09:00 版) <http://www.isotopicmaps.org/sam/>