<Book>
   <Title>Harry Potter</Title>
   <editorial>M<previous>Sort</previous></editorial>
   <languaje>ESP<previous>EU</previous></languaje>
   <nationality>ESP</nationality>
</Book>

<languaje>
    <xsl:value-of select="Book/languaje"/>
</languaje>

<xsl:value-of select="Book/languaje"/>

<xsl:value-of select="Book/languaje/text()" />

<xsl:for-each select="Book/languaje/text()">
    <xsl:value-of select="."/>
</xsl:for-each>

<xsl:apply-templates select="Book/languaje/text()" />

<xsl:apply-templates select="Book/languaje" />

<!-- And on the template level the following -->
<xsl:template match="languaje/previous" />

'ESP'+'' = 'ESP'