key from one file to another set of files

Dear All,

input.xml

<articles>
   <row>
         <col>4039</col>
         <col>Review Articles</col>
         <col>1</col>
      </row>
      <row>
         <col>3957</col>
         <col>Review Articles</col>
         <col>9</col>
      </row>
      <row>
         <col>3986</col>
         <col>Papers</col>
         <col>22</col>
      </row>
      <row>
         <col>3985</col>
         <col>Papers</col>
         <col>29</col>
      </row>
</articles>

x number of article.xml files with content:

1.xml

<article>
<aid>4039</aid>
<author>nnn</author>
<title>xxxxx<title>
</article>

2.xml

<article>
<aid>3957</aid>
<author>nnn</author>
<title>xxxxx<title>
</article>

3.xml

<article>
<aid>3986</aid>
<author>nnn</author>
<title>xxxxx<title>
</article>

4.xml

<article>
<aid>3985</aid>
<author>nnn</author>
<title>xxxxx<title>
</article>

Required output:

<cover-body>
<section>
<section-title>Review Articles</section-title>
<para><aid>4039</aid> <author>nnn</author> <title>xxxxx<title>
<page>1</page></para>
<para><aid>3957</aid> <author>nnn</author> <title>xxxxx<title>
<page>9</page></para>
</section>
<section>
<section-title>Papers</sectitle>
<para><aid>3986</aid> <author>nnn</author> <title>xxxxx<title>
<page>1</page></para>
<para><aid>3985</aid> <author>nnn</author> <title>xxxxx<title>
<page>9</page></para>
</section>
<cover-body>

XSL:
<xsl:template match="/" name="main">
<cover-body>
			<xsl:for-each select="collection('file:///D:/cover/sample
xmls/pageall/else/nima?select=*.xml;recurse=yes;on-error=ignore')">
				<xsl:variable name="a" select="."/>
				<xsl:if test="key('order', '$a/article/item-info/aid')">
				<xsl:if test="(document('input.xml')/articles/row/col[2])[1]">
				<section>
				<section-title><xsl:value-of select="."/></section-title>
				<para>
					<aid>
						<xsl:value-of select="$a/article/item-info/aid"/>
					</aid>
					<aug>
						<xsl:apply-templates select="$a/article/head/ce:author-group/ce:author"/>
					</aug>
					<article>
						<xsl:value-of select="$a/article/head/ce:title"/>
					</article>
					<page>
						<xsl:value-of select="document('input.xml')/articles/row/col[3]"/>
					</page>
				</para>
				</section>
				</xsl:if>
				</xsl:if>
			</xsl:for-each>
		</cover-body>
</xsl:template>

The key is not working for me. i have tried adding the document() in
the match but it is showing the error.

Regards,
Ganesh