1. Extensible Markup Language (XML), Webpage: 〈http://www.w3schools.com/XML/〉.
2. Creating XML Views Using Annotated XDR Schemas, Microsoft Corporation Webpage: 〈http://msdn.microsoft.com/library/default.asp?url=/library/en-us/xmlsql/ac_mschema_5cfn.asp〉.
3. SilkRoute: trading between relational and XML;Fernandez,2000
4. Document Type Definition (DTD), Webpage: 〈http://ww.w3schools.com/DTD/〉.
5. XML Schema, Webpage: 〈http://www.w3schools.com/schema/〉.