fix

--- a/doc-src/manual.bib	Mon Nov 05 15:01:21 2007 +0100
+++ b/doc-src/manual.bib	Mon Nov 05 15:04:19 2007 +0100
@@ -604,7 +604,7 @@
   author        = {Alexander Krauss},
   title         = {Defining Recursive Functions in {Isabelle/HOL}},
   institution   = TUM,
-  note          = {\url{http://isabelle.in.tum.de/doc/codegen.pdf}}
+  note          = {\url{http://isabelle.in.tum.de/doc/functions.pdf}}
 }
 
 @Book{kunen80,