XSL Grouping items by a tag not an attribute

I'm trying to work out how to use XSL to group an XML by the tag . Basically I want all the records to output the A's first, then the B's, then the C's if they existed which they don't in this example.

<PAYSLIP>
 <RECORD.MISC>
  <EMP_ID>0009011</EMP_ID>
  <ITEM.MISC>
   <ID>1001</ID>
   <DESCRIPTION>First Job Pay</DESCRIPTION>
   <VALUE>1000</VALUE>
   <SOURCE>A</SOURCE>
  </ITEM.MISC>
  <ITEM.MISC>
   <ID>1001</ID>
   <DESCRIPTION>Second Job Pay</DESCRIPTION>
   <VALUE>500</VALUE>
   <SOURCE>B</SOURCE>  
  </ITEM.MISC> 
  <ITEM.MISC>
   <ID>1001</ID>
   <DESCRIPTION>Car Allowance</DESCRIPTION>
   <VALUE>50</VALUE>
   <SOURCE>A</SOURCE>  
  </ITEM.MISC> 
 </RECORD.MISC>
</PAYSLIP>

The output required is:

>A
>First Job Pay  1000
>Car Allowance  50
>B
>Second Job Pay 500

I can achieve this with the following XSL but can't work out how to use a for-each-group or key statement to do this? At present I am going to have to repeat this piece of code for each letter of the alphabet which is not very efficient so I would be keen to learn another way to do this?

<xsl:for-each select="ITEM.MISC[SOURCE='A']">
<tr><xsl:value-of select="SOURCE"/></tr>
<tr>
 <td class="description">
   <xsl:value-of select="DESCRIPTION"/>
 </td>
 <td></td>
 <td class="value">
   <xsl:call-template name="formatnumber">
     <xsl:with-param name="value"><xsl:value-of select="VALUE"/></xsl:with-param>
   </xsl:call-template>
 </td>
</tr>
</xsl:for-each>
<xsl:for-each select="ITEM.MISC[SOURCE='B']">
<tr><xsl:value-of select="SOURCE"/></tr>
<tr>
 <td class="description">
   <xsl:value-of select="DESCRIPTION"/>
 </td>
 <td></td>
 <td class="value">
   <xsl:call-template name="formatnumber">
     <xsl:with-param name="value"><xsl:value-of select="VALUE"/></xsl:with-param>
   </xsl:call-template>
 </td>
</tr>
</xsl:for-each>

Any help much appreciated!