MSSQL server - How to return values from multiple nodes in XML in single field

DECLARE @xml xml
SET @Xml = '<FIELD NAME="NAME" BASE="5179827" COUNT="4">
  <TOKEN TEXT="a">...</TOKEN>
  <TOKEN TEXT="b">...</TOKEN>
  <TOKEN TEXT="a">...</TOKEN>
  <TOKEN TEXT="b">...</TOKEN>
  <TOKEN TEXT="a">...</TOKEN>
  <TOKEN TEXT="c">...</TOKEN>
</FIELD>'

SELECT
  x.query('data(TOKEN/@TEXT)') AS List
 ,x.query('distinct-values(TOKEN/@TEXT)') AS DistinctList
 , x.query('<data>
    {
     for $x in distinct-values(TOKEN/@TEXT)
     return 
      (concat($x, ","))
    }
   </data>
 ').query('data/text()') AS CommaSeparatedList
FROM @xml.nodes('/FIELD') AS d(x)

References

http://www.olcot.co.uk/sql-blogs/using-xquery-to-remove-duplicate-values-or-duplicate-nodes-from-an-xml-instance