<?xml version="1.0"?>
<dblp>
<article key="journals/jsyml/Quine56" mdate="2003-11-20">
<author>W. V. Quine</author>
<title>On Formulas with Valid Cases.</title>
<pages>148</pages>
<year>1956</year>
<volume>21</volume>
<journal>J. Symb. Log.</journal>
<number>2</number>
<url>db/journals/jsyml/jsyml21.html#Quine56</url>
</article>
</dblp>
