source 

indicates a bibliographic description or other resource documenting the
principles underlying the normalization carried out.

Attribute Information

Source 

<xs:attribute name="source" type="xs:anyURI">
  <xs:annotation>
    <xs:documentation>indicates a bibliographic description or other resource documenting the principles underlying the normalization carried out.</xs:documentation>
  </xs:annotation>
</xs:attribute>

Sample