>>>You've got document() and doc()....

Changed

    <xsl:variable name="extNode"
select="doc('file:///C:/book-type/book_meta.xml')"/>

<xsl:value-of select="doc($extNode)/book-meta/book[1]/@author"/>

Or tried alternatively document() on both code.

Still no success

Something terribly missing.

Thanks,
Pankaj