[racket] xml processing question

Hi there, 
I'd like to know how to idiomatically handle xml using racket's xml. 

Let's assume a minimal example like this:


(define xmlin "
<doc>
  <name>Some software</name>
  <more licence='gpl' checked='2010-12-10'/>
  <ref id='someref'/>
  <author id='John Doe'/>
</doc>")


(define xe (string->xexpr xmlin))
or
(define xe (xml->xexpr (document-element (read-xml (open-input-string
xmlin))))) 

Now my question is, how would I retrieve the contents of the xml
string? 

Do I have to work thru the xexpr by myself or are there some
predefined procedures available which I perhaps didn't recognize when
looking at the documentation?






-- 
Manfred