Fixed index references to modules.
diff --git a/Doc/lib/libmarshal.tex b/Doc/lib/libmarshal.tex
index 16472db..fa86c03 100644
--- a/Doc/lib/libmarshal.tex
+++ b/Doc/lib/libmarshal.tex
@@ -20,8 +20,8 @@
\code{pickle} and \code{shelve}. The \code{marshal} module exists
mainly to support reading and writing the ``pseudo-compiled'' code for
Python modules of \samp{.pyc} files.
-\stmodindex{pickle}
-\stmodindex{shelve}
+\refstmodindex{pickle}
+\refstmodindex{shelve}
\obindex{code}
Not all Python object types are supported; in general, only objects