DOCBOOK-APPS: XSL-Style: Referencing links

Good Morning list,
Can I reference a link? Like, I have a section with resources and want
to reference a link of it in the text.
   The source can be aquired here: <xref linkend="link_SW"/>.

And below, in my bibliography section:

 <biblioentry id="bib_sw">
  <abbrev>SW</abbrev>
    <title>My Own Home Page</title>
    <bibliosource id="link_SW">
       <ulink url="http://www.stephanwiesner.de/java">
         http://www.stephanwiesner.de/java 
       </ulink>
    </bibliosource>
 </biblioentry>


Neither HTML nor PDF style can render this.
I could use the ID of the biblioentry, but this would not give me just
the link.

Stephan Wiesner