<?xml version="1.0"?>
<dblp>
<article key="journals/jct/GarganoKV92" mdate="2004-07-19">
<author>Luisa Gargano</author>
<author>J&#225;nos K&#246;rner</author>
<author>Ugo Vaccaro</author>
<title>Qualitative Independence and Sperner Problems for Directed Graphs.</title>
<pages>173-192</pages>
<year>1992</year>
<volume>61</volume>
<journal>J. Comb. Theory, Ser. A</journal>
<number>2</number>
<url>db/journals/jct/jcta61.html#GarganoKV92</url>
</article>
</dblp>
