This should do the job:

<xsl:for-each select="/document/data/entry">
<xsl:choose>
	<xsl:when test=". = /document/references/ref">
		<b><xsl:value-of select="text()"/></b>
	</xsl:when> 
	<xsl:otherwise>  
		<i><xsl:value-of select="text()"/></i>
	</xsl:otherwise>
</xsl:choose>
</xsl:for-each>
 

Ben


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list