Fixed index module reference.
diff --git a/Doc/lib/libgdbm.tex b/Doc/lib/libgdbm.tex
index d82d655..ea655a3 100644
--- a/Doc/lib/libgdbm.tex
+++ b/Doc/lib/libgdbm.tex
@@ -5,7 +5,7 @@
This module is quite similar to the \code{dbm} module, but uses \code{gdbm}
instead to provide some additional functionality. Please note that
the file formats created by \code{gdbm} and \code{dbm} are incompatible.
-\bimodindex{dbm}
+\refbimodindex{dbm}
The \code{gdbm} module provides an interface to the GNU DBM
library. \code{gdbm} objects behave like mappings