<?xml version="1.0"?>
<dblp>
<article key="journals/is/LipskiM79" mdate="2003-11-27">
<author>Witold Lipski Jr.</author>
<author>V. Wiktor Marek</author>
<title>Information systems: on queries involving cardinalities.</title>
<pages>241-246</pages>
<year>1979</year>
<volume>4</volume>
<journal>Inf. Syst.</journal>
<number>1</number>
<url>db/journals/is/is4.html#LipskiM79</url>
</article>
</dblp>
