Media type: E-Article Title: Lecture Notes in Computer Science: Foundations of a New Proposal for Querying Relational Databases and XML Documents Contributor: García, Ana Fermoso; Larrea, María José Gil; Aguilar, Luis Joyanes; Labrador, Jesús Luis Díaz imprint: Springer Berlin Heidelberg, 2003 Published in: Lecture Notes in Computer Science Language: Not determined DOI: 10.1007/3-540-45068-8_76 ISSN: 0302-9743 Origination: Footnote: