[1] Character Model for the World Wide Web 1.0: Normalization ( (2012-04-27 11:15:23 +09:00 版)) <http://www.w3.org/TR/charmod-norm/#d0e854>

[2] Extensible Markup Language (XML) 1.1 (Second Edition) ( (2006-09-29 19:02:09 +09:00 版)) <http://www.w3.org/TR/2006/REC-xml11-20060816/#sec-CharNorm>