Add missing source links.
diff --git a/Doc/library/xml.etree.elementtree.rst b/Doc/library/xml.etree.elementtree.rst
index 71614c0..18c35aa 100644
--- a/Doc/library/xml.etree.elementtree.rst
+++ b/Doc/library/xml.etree.elementtree.rst
@@ -5,6 +5,9 @@
:synopsis: Implementation of the ElementTree API.
.. moduleauthor:: Fredrik Lundh <fredrik@pythonware.com>
+**Source code:** :source:`Lib/xml/etree/ElementTree.py`
+
+--------------
The :class:`Element` type is a flexible container object, designed to store
hierarchical data structures in memory. The type can be described as a cross