diff --git a/Doc/lectures.xml b/Doc/lectures.xml
index 51c827cbd6b03b8ef8b767edd065b4e1acc9296e..5d2e8774482ce410d91318ebf2bdaf1532eed741 100644
--- a/Doc/lectures.xml
+++ b/Doc/lectures.xml
@@ -25,9 +25,8 @@
     </legalnotice>
 
     <abstract>
-      <para>Document is also available in <link
-      xlink:href="printversion.pdf">PDF</link> and <link
-      xlink:href="lectures.epub">Epub</link> format.</para>
+      <para>This Document is also available <link linkend="ava">other
+      formats</link>.</para>
 
       <para><mediaobject>
           <imageobject>
diff --git a/Doc/preface.xml b/Doc/preface.xml
index 273733521872c572ac78ea99993ee90041c8c66b..b33be9023887c5769f64dec19185b9b2bfe1f407 100644
--- a/Doc/preface.xml
+++ b/Doc/preface.xml
@@ -10,7 +10,7 @@
 
   <para>This document is available in the following formats:</para>
 
-  <glosslist>
+  <glosslist xml:id="availableFormats">
     <glossentry>
       <glossterm><uri
       xlink:href="https://freedocs.mi.hdm-stuttgart.de/webhelp">https://freedocs.mi.hdm-stuttgart.de/webhelp</uri></glossterm>