1. J. Paoli, M. Sperberg-McQueen, F. Yergeau, J. Cowan, T. Bray, E. Maler, Extensible markup language (XML) 1.1 (second edition), W3C recommendation, W3C. http://www.w3.org/TR/2006/REC-xml11-20060816 (August 2006).
2. XML 1.1 Bible;Harold,2004
3. J. Simeon, A. Berglund, S. Boag, J. Robie, D. Chamberlin, M. Fernandez, M. Kay, XML path language (XPath) 2.0 (second edition), W3C recommendation, W3C. http://www.w3.org/TR/2010/REC-xpath20-20101214/ (December 2010).
4. J. Marsh, M. Fernandez, N. Walsh, A. Malhotra, M. Nagy, A. Berglund, XQuery 1.0 and XPath 2.0 data model (XDM) (second edition), W3C recommendation, W3C. http://www.w3.org/TR/2010/REC-xpath-datamodel-20101214/ (December 2010).
5. International standard: Information technology—Database languages—SQL, Tech. Rep.,2003