P. Faltstrom; P. Hoffman; A. Costello. <a href='http://www.rfc-editor.org/rfc/rfc3490.txt'><cite>Internationalizing Domain Names in Applications (IDNA).</cite></a> March 2003. Internet RFC 3490. URL: <a href='http://www.rfc-editor.org/rfc/rfc3490.txt'>http://www.rfc-editor.org/rfc/rfc3490.txt</a>