<?xml version="1.0"?>
<dblp>
<article key="journals/cacm/Johnson09" mdate="2009-09-18">
<author>Bruce Johnson</author>
<title>Reveling in constraints.</title>
<pages>44-48</pages>
<year>2009</year>
<volume>52</volume>
<journal>Commun. ACM</journal>
<number>9</number>
<ee>http://doi.acm.org/10.1145/1562164.1562181</ee>
<url>db/journals/cacm/cacm52.html#Johnson09</url>
</article>
</dblp>
