Add links to helpful external resources.
diff --git a/Doc/library/math.rst b/Doc/library/math.rst
index 4ecd14e..4d566a5 100644
--- a/Doc/library/math.rst
+++ b/Doc/library/math.rst
@@ -100,6 +100,10 @@
occasionally double-round an intermediate sum causing it to be off in its
least significant bit.
+ For further discussion and two alternative approaches, see the `ASPN cookbook
+ recipes for accurate floating point summation
+ <http://code.activestate.com/recipes/393090/>`_\.
+
.. versionadded:: 2.6