-<a href="/SEX.html">Stream EXchange</a>
-and
-<a href="http://fex.rus.uni-stuttgart.de/usecases/anonymous.html">anonymous usage</a>.
-
+<a href="$TA$/SEX.html">Stream EXchange</a> and
+<<
+ my $a = "/usecases/anonymous.html";
+ print "<a href=\"";
+ print "http://fex.rus.uni-stuttgart.de" unless -s "$docdir$a";
+ print "$a\">anonymous usage</a>";
+>>