[1] Voice Extensible Markup Language (VoiceXML) 3.0 ( 版) <http://www.w3.org/TR/2008/WD-voicexml30-20081219/>
[2] Voice Extensible Markup Language (VoiceXML) 3.0 ( 版) <http://www.w3.org/TR/2009/WD-voicexml30-20091203/>
[3] Voice Extensible Markup Language (VoiceXML) 3.0 ( ( 版)) <http://www.w3.org/TR/2010/WD-voicexml30-20101216/>