<?xml version="1.0"?>
<dblp>
<article key="journals/tois/SchableW94" mdate="2006-04-03">
<author>Peter Sch&#228;uble</author>
<author>Beat W&#252;thrich</author>
<title>On the Expressive Power of Query Languages.</title>
<pages>69-91</pages>
<year>1994</year>
<volume>12</volume>
<journal>ACM Trans. Inf. Syst.</journal>
<number>1</number>
<ee>http://doi.acm.org/10.1145/174608.174611</ee>
<url>db/journals/tois/tois12.html#SchableW94</url>
</article>
</dblp>
