<?xml version="1.0"?>
<dblp>
<inproceedings key="conf/focs/Greibach67" mdate="2006-04-25">
<title>An Infinite Hierarchy of Context-Free Languages</title>
<author>Sheila A. Greibach</author>
<pages>32-36</pages>
<crossref>conf/focs/FOCS8</crossref>
<year>1967</year>
<booktitle>FOCS</booktitle>
<url>db/conf/focs/focs67.html#Greibach67</url>
</inproceedings>

</dblp>
