1.2 Normative References reads in part:

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[DATETIME] P. Biron and A. Malhotra, XML Schema Part 2: Datatypes Second Edition. 28 October 2004. W3C REC-xmlschema-2,, Sec 3.2.7, dateTime. http://www.w3.org/TR/xmlschema-2
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First, the URL given resolves to XML Schema Part 2: Datatypes Second Edition and not to Section 3.2.7

Second, the citation itself is incorrect. The correct citation as given by the W3C bibliography generator (http://www.w3.org/2002/01/tr-automation/tr-biblio-ui) is:

XMLSCHEMA-2
XML Schema Part 2: Datatypes Second Edition , P. V. Biron, A. Malhotra, Editors, W3C Recommendation, 28 October 2004, http://www.w3.org/TR/2004/REC-xmlschema-2-20041028/ . Latest version available at http://www.w3.org/TR/xmlschema-2/ .

The better course would be to use the XMLSCHEMA-2 as your normative reference and then in the standard, when appropriate, you say:

XMLSCHEMA-2, section 3.2.7 dateTime, which gives you the normative reference and a pointer into the reference to a specific location.