title: supporting top-k join queries in relational databases walid g. aref , ahmed k. elmagarmid , ihab f. ilyas vldb 2003. authors: nan. venue: nan. year: nan
title: relational databases for querying xml documents : limitations and opportunities very large data bases. authors: jayavel shanmugasundaram , kristin tufte , chun zhang , gang he , david j. dewitt , jeffrey f. naughton. venue: nan. year: 1999.0