<?xml version="1.0"?>
<dblp>
<article key="journals/apal/Vlach94" mdate="2003-11-28">
<author>Alan D. Vlach</author>
<title>Hyperarithmetical Relations in Expansions of Recursive Structures.</title>
<pages>163-196</pages>
<year>1994</year>
<volume>66</volume>
<journal>Ann. Pure Appl. Logic</journal>
<number>2</number>
<url>db/journals/apal/apal66.html#Vlach94</url>
</article>
</dblp>
