title: a general techniques for querying xml documents using a relational database system. authors: stratis viglas , eugene j. shekita , rajasekar krishnamurthy , jayavel shanmugasundaram , jeffrey f. naughton , jerry kiernan , igor tatarinov. venue: sigmod record. year: 2001
title: unisql 's next-generation object-relational database management system. authors: albert d'andrea , phil janus. venue: acm sigmod record. year: 1996