title: semantic integrity support in sql : 1999 and commercial ( object - ) relational database management systems. authors: michael gertz , can türker. venue: vldb j.. year: 2001
title: semantic integrity support in sql :1999 and commercial ( object - ) relational database management systems. authors: can t &#252; rker , michael gertz. venue: the vldb journal -- the international journal on very large data bases. year: 2001