Update link to PythonWare library page.
diff --git a/Doc/lib/libundoc.tex b/Doc/lib/libundoc.tex
index e8f3736..18c9db7 100644
--- a/Doc/lib/libundoc.tex
+++ b/Doc/lib/libundoc.tex
@@ -16,8 +16,8 @@
\item[\module{Tkinter}]
--- Interface to Tcl/Tk for graphical user interfaces; Fredrik Lundh
is working on this one! See
-\citetitle[http://www.pythonware.com/library/]{An Introduction to
-Tkinter} at \url{http://www.pythonware.com/library/} for on-line
+\citetitle[http://www.pythonware.com/library.htm]{An Introduction to
+Tkinter} at \url{http://www.pythonware.com/library.htm} for on-line
reference material.
\item[\module{Tkdnd}]