Denilson Barbosa Juliana Freire Alberto O. Mendelzon Information Preservation in XML-to-Relational Mappings. 66-81 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3186&spage=66 2004 conf/xsym/2004 XSym db/conf/xsym/xsym2004.html#BarbosaFM04