[3] XBL 2.0 ( (2012-05-03 02:23:03 +09:00 版)) <http://dev.w3.org/2006/xbl2/Overview.html#the-bound-element-pseudo-class>
[4] XML Binding Language (XBL) 2.0 ( (2007-03-16 22:20:16 +09:00 版)) <http://www.w3.org/TR/2007/CR-xbl-20070316/#the-bound-element>