Use \citetitle and \programopt as appropriate.
diff --git a/Doc/lib/libundoc.tex b/Doc/lib/libundoc.tex
index 2967cb8..e8f3736 100644
--- a/Doc/lib/libundoc.tex
+++ b/Doc/lib/libundoc.tex
@@ -14,8 +14,9 @@
\begin{description}
\item[\module{Tkinter}]
---- Interface to Tcl/Tk for graphical user interfaces;
-Fredrik Lundh is working on this one! See \emph{An Introduction to
+--- 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
reference material.