1. T. Bray, J. Paoli, C.M. Sperberg-McQueen, E. Maler, Extensible Markup Language(XML) 1.0 (third Ed.), W3C Recommendation. .
2. The Lorel query language for semistructured data;Abiteboul;International Journal on Digital Libraries,1997
3. S. Abiteboul, Query semi-structured data, in: Proceedings of the Sixth International Conference on Database Theory(ICDT), 1997, pp. 1–18.
4. S.Derose, E.Maler, D. Orchard, XML Linking Language(XLink), version 1.0, W3C Recommendation. .
5. S. Boag, D. Chamberlin, D. Florescu, J. Robie, J. Simeon, XQuery 1.0: An XML Query Language, W3C Recommendation. .